[R] Downloading Reuters data from R

2008-12-11 Thread Shubha Vishwanath Karanth
Hi R,

 

Can we download Reuters (3000 Xtra) data from R? Does ODBC package help
me in this? Or otherwise, is there a way to extract daily closing prices
data of Reuters from R?

 

 

Thank you very much,

Shubha

This e-mail may contain confidential and/or privileged i...{{dropped:13}}

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Re: [R] 2-Y-axes on same plot

2008-12-11 Thread Jim Lemon

Joe Trubisz wrote:

Hi...

Is this possible in R?

I have 2-sets of data, that were collected simultaneously using 
2-different data acquisition schemes.

The x-values are the same for both.
The y-values have different ranges (16.4-37.5 using one method, 
557-634 using another).


In theory, if you plot both plots on top of each other, the graphs 
should overlap. The problem I'm having is trying to have to different 
sets of y-values appear in the same graph, but scaled in the same 
vertical space. I've seen this done in publications, but not sure if 
it can be done in R.

Hi Joe,
Check out twoord.plot in the plotrix package.

Jim

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Re: [R] A package to set up a questionnaire enter data

2008-12-11 Thread Jim Lemon

CE.KA wrote:

Hi R users,
Is there a Package in R to
- set up a questionnaire?
- enter data?
  

Hi CE.KA,
I don't know, but I have written a general purpose questionnaire program 
in Tcl-Tk that will administer the questionnaire and record the 
responses. If you don't find anything, let me know.


Jim

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Re: [R] means of a column within groups of a data frame

2008-12-11 Thread Jim Lemon

John Sorkin wrote:

R 2.8.0
windows XP

I would like to divide the rows of data frame into five groups and then get the 
mean of one column within the five groups. I have accomplished this using the 
code below, but I hope there is an easier way, i.e. some function that I can 
call

# create five groups.
cut(data$BMI,5)
# get mean of AAMTCARE within each of the five groups
mean(data[data[,BMIcuts]==(13.3,21.9],AAMTCARE])
mean(data[data[,BMIcuts]==(21.9,30.5],AAMTCARE])
mean(data[data[,BMIcuts]==(30.5,39.1],AAMTCARE])
mean(data[data[,BMIcuts]==(39.1,47.7],AAMTCARE])
mean(data[data[,BMIcuts]==(47.7,56.3],AAMTCARE]) 
  

Hi John,
Have a look at brkdn in the prettyR package.

data$BMIcuts-cut(data$BMI,5)
brkdn(BMI~BMIcuts,data)

Jim

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[R] Fwd: Jacobi Plane Rotations in R

2008-12-11 Thread Jan de Leeuw
http://idisk.mac.com/jdeleeuw-Public/jacobi

This is paper/software for various techniques based on Jacobi plane  
rotations.

There is R code for

-- classical cyclical Jacobi Eigen diagonalization
-- Jacobi-based SVD diagonalization
-- approximate simultaneous diagonalization of symmetric matrices (De  
Leeuw/Pruzansky 1978)
-- approximate simultaneous diagonalization of rectangular matrices  
(TUCKER-2)
-- approximate body diagonalization of three-way arrays (orthogonal  
INDSCAL)
-- TUCKER-3 for three-way arrays (three rotations meet a core)
-- PREHOM/MCA approximate KPL-diagonalization of the Burt matrix (De  
Leeuw/Bekker 1982)

==
Jan de Leeuw, 11667 Steinhoff Rd, Frazier Park, CA 93225
home 661-245-1725 skype 661-347-0667 global 254-381-4905
.mac: jdeleeuw +++  aim: deleeuwjan +++ skype: j_deleeuw
==
 Many nights on the road
and not dead yet ---
the end of autumn.   (Basho 1644-1694)



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Re: [R] Logical inconsistency

2008-12-11 Thread Kenn Konstabel
Rounding can do no good because

round(8.8,1)-round(7.8,1)1
# still TRUE
round(8.8)-round(7.7)1
# FALSE

What you might do is compute a-b-1 and compare it to a very small number:

(8.8-7.8-1)  1e-10
# TRUE

K


On Wed, Dec 10, 2008 at 11:47 AM, emma jane [EMAIL PROTECTED] wrote:

 Thanks Greg, that does make sense.  And I've solved the problem by
 rounding the variables before taking the difference between them.

 Thanks to all who replied.

 Emma JaneÂ




 
 From: Greg Snow [EMAIL PROTECTED]

 .com.br; Wacek Kusnierczyk [EMAIL PROTECTED]; Chuck
 Cleland [EMAIL PROTECTED]
 Cc: R help [EMAIL PROTECTED]
 Sent: Tuesday, 9 December, 2008 16:30:08
 Subject: RE: [R] Logical inconsistency

 Some (possibly all) of those numbers cannot be represented exactly, so
 there is a chance of round off error whenever you do some arithmetic,
 sometimes the errors cancel out, sometimes they don't.  Consider:

  print(8.3-7.3, digits=20)
 [1] 1.001
  print(11.3-10.3, digits=20)
 [1] 1

 So in the first case the rounding error gives a value that is slightly
 greater than 1, so the greater than test returns true (if you round the
 result before comparing to 1, then it will return false).  In the second
 case the uncertainties cancelled out so that you get exactly 1 which is not
 greater than 1 an so the comparison returns false.

 Hope this helps,

 --
 Gregory (Greg) L. Snow Ph.D.
 Statistical Data Center
 Intermountain Healthcare
 [EMAIL PROTECTED]
 801.408.8111


  -Original Message-
  From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
  project.org] On Behalf Of emma jane
  Sent: Tuesday, December 09, 2008 7:02 AM
  To: Bernardo Rangel Tura; Wacek Kusnierczyk; Chuck Cleland
  Cc: R help
  Subject: Re: [R] Logical inconsistency
 
  Many thanks for your help, perhaps I should have set my query in
  context  !
 
  I'm simply calculating an indicator variable [0,1] based on the whether
  the difference between two measured variables is  1 or =1.
 
  I understand the FAQ about floating point arithmetic, but am still
  puzzled that it only apparently applies to certain elements, as
  follows:
 
  8.8 - 7.8  1
   TRUE
 
  8.3 - 7.3  1
   TRUE
 
  However,
 
  10.2 - 9.2  1
  FALSE
 
  11.3 - 10.31
  Â FALSE
 
  Emma Jane
 
 
 
 
  
  From: Bernardo Rangel Tura [EMAIL PROTECTED]
  To: Wacek Kusnierczyk [EMAIL PROTECTED]
  Cc: R help [EMAIL PROTECTED]
  Sent: Saturday, 6 December, 2008 10:00:48
  Subject: Re: [R] Logical inconsistency
 
  On Fri, 2008-12-05 at 14:18 +0100, Wacek Kusnierczyk wrote:
   Berwin A Turlach wrote:
Dear Emma,
   
On Fri, 5 Dec 2008 04:23:53 -0800 (PST)
 
   
   
Please could someone kindly explain the following inconsistencies
I've discovered__when performing logical calculations in R:
   
8.8 - 7.8  1
   
TRUE
   
8.3 - 7.3  1
   
TRUE
   
   
Gladly:Â  FAQ 7.31
http://cran.at.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-
  th
ink-these-numbers-are-equal_003f
   
   
  
   well, this answer the question only partially.  this explains why a
   system with finite precision arithmetic, such as r, will fail to be
   logically correct in certain cases.  it does not explain why r, a
   language said to isolate a user from the underlying implementational
   choices, would have to fail this way.
  
   there is, in principle, no problem in having a high-level language
   perform the computation in a logically consistent way.  for example,
   bc is an arbitrary precision calculator language, and has no
  problem
   with examples as the above:
  
   bc  8.8 - 7.8  1
   # 0, meaning 'no'
  
   bc  8.3 - 7.3  1
   # 0, meaning 'no'
  
   bc  8.8 - 7.8 == 1
   # 1, meaning 'yes'
  
  
   the fact that r (and many others, including matlab and sage, perhaps
   not
   mathematica) does not perform logically here is a consequence of its
   implementation of floating point arithmetic.
  
   the faq you were pointed to, and its referring to the goldberg's
   article, show that r does not successfully isolate a user from
  details
   of the lower-level implementation.
  
   vQ
 
  Well, first of all for 8.-7.3 is not equal to 1 [for computers]
 
   8.3-7.3-1
  [1] 8.881784e-16
 
  But if you use only one digit precision
 
   round(8.3-7.3,1)-1
  [1] 0
   round(8.3-7.3,1)-10
  [1] FALSE
   round(8.3-7.3,1)==1
  [1] TRUE
 
 
  So the problem is the code write and no the software
 
  --
  Bernardo Rangel Tura, M.D,MPH,Ph.D
  National Institute of Cardiology
  Brazil
 
 
 
 Â  Â  Â  Â  [[alternative HTML version deleted]]



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[R] Coxian Distribution

2008-12-11 Thread Borja Soto Varela
Hello R-users.
I want to know if there is in R the distribution and density function of the
Coxian. If there isn't, It will help if someone has written this functions.

Thanks
Borja

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[R] Rotate basic plot (scatter) in R

2008-12-11 Thread Michael Hegenloh
Dear all,

I was trying to rotate a plot using R. I tried most of the examples offered
here in this forum, but for some reason it is not working for a Scatterplot
or in my case: plot (x,y). With a histogram I had no problems.
Is it not possible to rotate a simple plot?

Thanks a lot,

Michael

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Re: [R] snowfall sfInit error

2008-12-11 Thread Jochen Knaus

Dear Mr. Ripley,

indeed that it true. sfInit() currently have a bug on Windows depending 
on the usage of the Linux tools and the broken Exceptionhandling. Too 
bad I never tested it accordingly on Windows (as we do not have any 
Windows machines in our institute).


snowfall 1.62 is in the pipe with many other fixes (e.g. NetWorkSpaces 
usage) and I will include a Windows workaround in it.


It will go out for testing at the beginning of the week and should be on 
CRAN end of the week.


Best regards, Jochen Knaus




On Sat, 6 Dec 2008, [EMAIL PROTECTED] wrote:


Dear all,

I am trying to execute the simple example in snowfall
http://cran.r-project.org/web/packages/snowfall/vignettes/snowfall.pdf 
...


require(snow)
require(snowfall)
sfInit( parallel=TRUE, cpus=2 )
sfLapply( 1:10, exp )
sfStop()

I have installed the snow and snowfall packages in R on a machine with
windows xp, however, after running the sfInit( parallel=TRUE, cpus=2 )
line I get an error ...

Error in system(whoami, intern = TRUE, ignore.stderr = TRUE) :
 whoami not found
Error in paste(sep = _, R, uname, format(Sys.time(),
%H%M%S_%m%d%y)) :
 object uname not found

I am the only (administrator) user of the computer. It has a dual core
processor, and is not networked.

I would be greatful if someone could tell me how to proceed.


Follow the posting guide (see the footer of this message) and talk to 
the maintainer of 'snowfall'.  Most likely it is not intended to be 
used on Windows, but has not declared that.  'whoami' and 'uname' are 
Unix programs, not Windows ones, but R's Sys.info() provides 
equivalent information.




Kind regards

Chibisi

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[R] call lattice function in a function passing groups argument

2008-12-11 Thread Thomas Zumbrunn
I'm trying to use a lattice function within a function and have problems 
passing the groups argument properly. Let's say I have a data frame

d - data.frame(x = rnorm(100), y = c(a, b))

and want to plot variable x in a densityplot, grouped by the variable y, then 
I would do something like

densityplot(~ x, d, groups = y)

If however I wanted to call the function densityplot within a function and 
pass the groups argument as an argument of that function, how would I have 
to proceed? It is not as straightforward as

f - function(data, groupvar) {
  densityplot(~ x, data, groups = groupvar)
}

probably because the lattice function densityplot.formula preprocesses 
the groups argument with

groups - eval(substitute(groups), data, environment(formula))

It there a way how I could pass the groups argument in the function f?

Thanks for any hints,
Thomas Zumbrunn

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Re: [R] Rotate basic plot (scatter) in R

2008-12-11 Thread Philipp Pagel
 I was trying to rotate a plot using R. I tried most of the examples offered
 here in this forum, but for some reason it is not working for a Scatterplot
 or in my case: plot (x,y). With a histogram I had no problems.
 Is it not possible to rotate a simple plot?

I'm not 100% sure what exactly you mean by 'rotate'. I'll assume
you mean rotation of the entire canvas on the output device. For
the postscript device you can use the 'horizontal' option to
switch between portait and landscape orientation. Is that what
you meant? Probably not, because you mentioned that you succeeded
with histograms. Maybe you should give us alittle more
information, e.g. what exactly you need and what you did in the
case of histograms.

cu
Philipp

-- 
Dr. Philipp Pagel
Lehrstuhl für Genomorientierte Bioinformatik
Technische Universität München
Wissenschaftszentrum Weihenstephan
85350 Freising, Germany
http://mips.gsf.de/staff/pagel

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Re: [R] Simplex function in R

2008-12-11 Thread axionator
Hi,
in the first example, your feasible set is just one point (the one
that fulfills the 3 equations) and thus there is only this one point
which can maximize the objective function. In the second case, the
feasible set is a line. But the simplex algorithm tries to find an
optimizing value of the objective on a convex polyhedron. So the
simplex function may be inappropriate to find all feasible solutions.

HTH
Armin

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[R] Principal Component Analysis - Selecting components? + right choice?

2008-12-11 Thread Corrado
Dear R gurus,

I have some climatic data for a region of the world. They are monthly averages 
1950 -2000 of precipitation (12 months), minimum temperature (12 months), 
maximum temperature (12 months). I have scaled them to 2 km x 2km cells, and 
I have around 75,000 cells.

I need to feed them into a statistical model as co-variates, to use them to 
predict a response variable.

The climatic data are obviously correlated: precipitation for January is 
correlated to precipitation for February and so on  even precipitation 
and temperature are heavily correlated. I did some correlation analysis and 
they are all strongly correlated.

I though of running PCA on them, in order to reduce the number of co-variates 
I feed into the model.

I run the PCA using prcomp, quite successfully. Now I need to use a criteria 
to select the right number of PC. (that is: is it 1,2,3,4?)

What criteria would you suggest?

At the moment, I am using a criteria based on threshold, but that is highly 
subjective, even if there are some rules of thumb (Jolliffe,Principal 
Component Analysis, II Edition, Springer Verlag,2002). 

Could you suggest something more rigorous?

By the way, do you think I would have been better off by using something 
different from PCA?

Best,
-- 
Corrado Topi

Global Climate Change  Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: [EMAIL PROTECTED]

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Re: [R] A package to set up a questionnaire enter data

2008-12-11 Thread David Croll



Hello,

For entering data alone, you would not need a package. For simple 
questionnaires, you could write a function.


It could go like this. For example you want to record people's names and 
their ages:


# Sets up an empty database
database - c()

enter_data - function() {
   show(Enter name:)
   name - as.character(readline())
  
   show(Enter age:)

   age - as.numeric(readline())
  
   # Appends data from one questionnaire to the

   # database
   database - rbind(database,data.frame(name,age))
  
   # Calls the function in order to proceed

   # with another questionnaire
  
   enter_data()
  
   # stop the function using the stop button when you are finished

   }

exporting database into a CSV or a text file should not be a problem 
with write.csv() or write.csv2().




Kind regards,


David Croll

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Re: [R] Simplex function in R

2008-12-11 Thread Gabor Grothendieck
Try the pseudo inverse:

m - rbind(c(1, 1, 1), c(1, 0, 1), c(0, 1, 0))
b - c(5, 2, 3)

library(MASS)
ginv(m) %*% b


On Thu, Dec 11, 2008 at 2:20 AM, Chris Line [EMAIL PROTECTED] wrote:
 I have a set of linear equations and would like to find any feasible 
 solution.  A simplex solution works in Case 1 below, but not in Case 2.  I 
 would be grateful for any help.

 Case 1: Find any feasible solution for the set of linear equations:
  a  +   b   +   c  = 5
  a  +   b  +  0c  = 4
 0a +   b   +   c  =  4

 Solution - a feasible (and unique) solution is a=1, b=3, c=1.

 The following R code returns a feasible solution:
 A3M = matrix(c(1,1,0,1,1,1,1,0,1),nrow=3)
 b3M = matrix(c(5,4,4),ncol=1)
 A1M = matrix(c(1,0,0,0,1,0,0,0,1),nrow=3)
 b1M = matrix(c(10,10,10),ncol=1)
 AM = matrix(c(1,1,1),nrow=1)
 simplex(a = AM, A1 = A1M, b1 = b1M, A2 = NULL, b2 = NULL, A3 = A3M, b3 = b3M, 
 maxi = TRUE)


 Case 2: Find any feasible solution for the set of linear equations
   a +   b   +   c  = 5
   a + 0b  +   c  = 2
 0a +   b   + 0c  = 3

 Solution - one feasible solution of many is a=1, b=3, c=1.  There are 
 infinite possible solutions in Case 2.

 However, the following R code fails to return any feasible solution:
 A3M = matrix(c(1,1,0,1,0,1,1,1,0),nrow=3)
 b3M = matrix(c(5,2,3),ncol=1)
 A1M = matrix(c(1,0,0,0,1,0,0,0,1),nrow=3)
 b1M = matrix(c(10,10,10),ncol=1)
 AM = matrix(c(1,1,1),nrow=1)
 simplex(a = AM, A1 = A1M, b1 = b1M, A2 = NULL, b2 = NULL, A3 = A3M, b3 = b3M, 
 maxi = TRUE)

 The code returns the error:
 Error in A.out[, basic] - iden(M) : subscript out of bounds

 Am I using the Simplex function incorrectly?  There may be a better way to 
 approach the problem of finding a feasible solution.

 Cheers,
 Chris.

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Re: [R] Principal Component Analysis - Selecting components? + right choice?

2008-12-11 Thread Stéphane Dray

You can have look to

*S. Dray*. On the number of principal components: A test of 
dimensionality based on measurements of similarity between matrices. 
/Computational Statistics and Data Analysis/, 52:2228-2237, 2008.


which is implemented in the testdim function of the ade4 package.


Cheers.

Corrado wrote:

Dear R gurus,

I have some climatic data for a region of the world. They are monthly averages 
1950 -2000 of precipitation (12 months), minimum temperature (12 months), 
maximum temperature (12 months). I have scaled them to 2 km x 2km cells, and 
I have around 75,000 cells.


I need to feed them into a statistical model as co-variates, to use them to 
predict a response variable.


The climatic data are obviously correlated: precipitation for January is 
correlated to precipitation for February and so on  even precipitation 
and temperature are heavily correlated. I did some correlation analysis and 
they are all strongly correlated.


I though of running PCA on them, in order to reduce the number of co-variates 
I feed into the model.


I run the PCA using prcomp, quite successfully. Now I need to use a criteria 
to select the right number of PC. (that is: is it 1,2,3,4?)


What criteria would you suggest?

At the moment, I am using a criteria based on threshold, but that is highly 
subjective, even if there are some rules of thumb (Jolliffe,Principal 
Component Analysis, II Edition, Springer Verlag,2002). 


Could you suggest something more rigorous?

By the way, do you think I would have been better off by using something 
different from PCA?


Best,
  


--
Stéphane DRAY ([EMAIL PROTECTED] )
Laboratoire BBE-CNRS-UMR-5558, Univ. C. Bernard - Lyon I
43, Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
Tel: 33 4 72 43 27 57   Fax: 33 4 72 43 13 88
http://biomserv.univ-lyon1.fr/~dray/

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Re: [R] ref card for data manipulation?

2008-12-11 Thread Vitalie Spinu

On Wed, 10 Dec 2008 18:29:43 +0100, Peter Dalgaard [EMAIL PROTECTED] wrote:



You (as many before you) have overlooked the ave() function, which can
replace the ordering as well the do.call(c,tapply())



Majority of questions on this list concern data manipulation. Many are repetitive. 
Overlooking like that will always happen unless some comprehensive data 
manipulation documentation is made.
I think many people would benefit if  a specialized data.manip ref.card were conceived. 


Tom Short's card is an excellent one but it does not cover high level packages 
like plyr, reshape, DoBy, and a few base data.manip functions are not there as 
well.

Vitalie.

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[R] getting ISO week

2008-12-11 Thread Gustaf Rydevik
Hi all,

Is there a simple function already implemented for getting the ISO
weeks of a Date object?
I couldn't find one, and so wrote my own function to do it, but would
appreciate a pointer to the default way. If a function is not yet
implemented, could the code below be of interest to submit to CRAN?

Best Regards,

Gustaf



getweek-function(Y,M=NULL,D=NULL){

  if(!class(Y)[1]%in%c(Date,POSIXt)) {
  date.posix-strptime(paste(c(Y,M,D),collapse=-),%Y-%m-%d)
  }
  if(class(Y)[1]%in%c(POSIXt,Date)){
date.posix-as.POSIXlt(Y)
Y-as.numeric(format(date.posix,%Y))
M-as.numeric(format(date.posix,%m))
D-as.numeric(format(date.posix,%d))
  }


  LY- (Y%%4==0  !(Y%%100==0))|(Y%%400==0)
  LY.prev- ((Y-1)%%4==0  !((Y-1)%%100==0))|((Y-1)%%400==0)
  date.yday-date.posix$yday+1
  jan1.wday-strptime(paste(Y,01-01,sep=-),%Y-%m-%d)$wday
  jan1.wday-ifelse(jan1.wday==0,7,jan1.wday)
  date.wday-date.posix$wday
  date.wday-ifelse(date.wday==0,7,date.wday)


  If the date is in the beginning, or end of the year,
  ### does it fall into a week of the previous or next year?
  Yn-ifelse(date.yday=(8-jan1.wday)jan1.wday4,Y-1,Y)
  Yn-ifelse(Yn==Y((365+LY-date.yday)(4-date.wday)),Y+1,Y)

  ##Set the week differently if the date is in the beginning,middle or
end of the year

  Wn-ifelse(
  Yn==Y-1,
  ifelse((jan1.wday==5|(jan1.wday==6 LY.prev)),53,52),
  ifelse(Yn==Y+1,1,(date.yday+(7-date.wday)+(jan1.wday-1))/7-(jan1.wday4))
  )
return(list(Year=Yn,ISOWeek=Wn))
}


-- 
Gustaf Rydevik, M.Sci.
tel: +46(0)703 051 451
address:Essingetorget 40,112 66 Stockholm, SE
skype:gustaf_rydevik

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and provide commented, minimal, self-contained, reproducible code.


[R] merging data.frames columnwise (rbind with different variables, lengths)

2008-12-11 Thread Stefan Uhmann

Dear List,

I have two dataframes with overlapping colnames and want to merge them. 
 Actually, what I want is more similar to rbind, but the dataframes 
differ in their columns. Here are the examples:


df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
df2 - data.frame(A = c(2), C = c(at home))

Here the desired result:

  A BC
1 1 m  at home
2 2 f away
3 2 NA at home

Thanks for any help,
Stefan

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Re: [R] merging data.frames columnwise (rbind with different variables, lengths)

2008-12-11 Thread ONKELINX, Thierry
Dear Stefan,

Why not use merge() if you want to merge two datasets? ;-)

df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
df2 - data.frame(A = c(2), C = c(at home))
merge(df1, df2, all = TRUE) 

HTH,

Thierry



ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium 
tel. + 32 54/436 185
[EMAIL PROTECTED] 
www.inbo.be 

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey

-Oorspronkelijk bericht-
Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Namens Stefan Uhmann
Verzonden: donderdag 11 december 2008 13:46
Aan: r-help@r-project.org
Onderwerp: [R] merging data.frames columnwise (rbind with different
variables,lengths)

Dear List,

I have two dataframes with overlapping colnames and want to merge them. 
  Actually, what I want is more similar to rbind, but the dataframes 
differ in their columns. Here are the examples:

df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
df2 - data.frame(A = c(2), C = c(at home))

Here the desired result:

   A BC
1 1 m  at home
2 2 f away
3 2 NA at home

Thanks for any help,
Stefan

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en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is
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[R] Extracting the name of an object into a character string

2008-12-11 Thread Philip Whittall
Dear List,

I am writing a function in R with the facility to store models for later
use in scoring.
It would be very useful if I could include in the name of the file
stored the name of
the model object being stored, this name being chosen by the user in the
function
call. A simple function to store the name of an object as a character
string would fit the
bill, but I have not found one. name() doesn't appear to do what I want,
maybe I'm using
it wrongly.  Any suggestions please ? I'm running 2.8.0 on windows XP,

Thanks,

Philip
 



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Re: [R] getting ISO week

2008-12-11 Thread Prof Brian Ripley

strftime(x, %V)

E.g.

strftime(as.POSIXlt(Sys.Date()), %V)

is 50, and you might want as.numeric() on it.

Note that this is OS-dependent, and AFAIR Windows does not have it.

On Thu, 11 Dec 2008, Gustaf Rydevik wrote:


Hi all,

Is there a simple function already implemented for getting the ISO
weeks of a Date object?
I couldn't find one, and so wrote my own function to do it, but would
appreciate a pointer to the default way. If a function is not yet
implemented, could the code below be of interest to submit to CRAN?

Best Regards,

Gustaf



getweek-function(Y,M=NULL,D=NULL){

 if(!class(Y)[1]%in%c(Date,POSIXt)) {
 date.posix-strptime(paste(c(Y,M,D),collapse=-),%Y-%m-%d)
 }
 if(class(Y)[1]%in%c(POSIXt,Date)){
date.posix-as.POSIXlt(Y)
Y-as.numeric(format(date.posix,%Y))
M-as.numeric(format(date.posix,%m))
D-as.numeric(format(date.posix,%d))
 }


 LY- (Y%%4==0  !(Y%%100==0))|(Y%%400==0)
 LY.prev- ((Y-1)%%4==0  !((Y-1)%%100==0))|((Y-1)%%400==0)
 date.yday-date.posix$yday+1
 jan1.wday-strptime(paste(Y,01-01,sep=-),%Y-%m-%d)$wday
 jan1.wday-ifelse(jan1.wday==0,7,jan1.wday)
 date.wday-date.posix$wday
 date.wday-ifelse(date.wday==0,7,date.wday)


 If the date is in the beginning, or end of the year,
 ### does it fall into a week of the previous or next year?
 Yn-ifelse(date.yday=(8-jan1.wday)jan1.wday4,Y-1,Y)
 Yn-ifelse(Yn==Y((365+LY-date.yday)(4-date.wday)),Y+1,Y)

 ##Set the week differently if the date is in the beginning,middle or
end of the year

 Wn-ifelse(
 Yn==Y-1,
 ifelse((jan1.wday==5|(jan1.wday==6 LY.prev)),53,52),
 ifelse(Yn==Y+1,1,(date.yday+(7-date.wday)+(jan1.wday-1))/7-(jan1.wday4))
 )
   return(list(Year=Yn,ISOWeek=Wn))
}


--
Gustaf Rydevik, M.Sci.
tel: +46(0)703 051 451
address:Essingetorget 40,112 66 Stockholm, SE
skype:gustaf_rydevik



--
Brian D. Ripley,  [EMAIL PROTECTED]
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax:  +44 1865 272595

__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] getting ISO week

2008-12-11 Thread Prof Brian Ripley

A slightly simpler version is

format(Sys.Date(), %V)


On Thu, 11 Dec 2008, Prof Brian Ripley wrote:


strftime(x, %V)

E.g.

strftime(as.POSIXlt(Sys.Date()), %V)

is 50, and you might want as.numeric() on it.

Note that this is OS-dependent, and AFAIR Windows does not have it.

On Thu, 11 Dec 2008, Gustaf Rydevik wrote:


Hi all,

Is there a simple function already implemented for getting the ISO
weeks of a Date object?
I couldn't find one, and so wrote my own function to do it, but would
appreciate a pointer to the default way. If a function is not yet
implemented, could the code below be of interest to submit to CRAN?

Best Regards,

Gustaf



getweek-function(Y,M=NULL,D=NULL){

 if(!class(Y)[1]%in%c(Date,POSIXt)) {
 date.posix-strptime(paste(c(Y,M,D),collapse=-),%Y-%m-%d)
 }
 if(class(Y)[1]%in%c(POSIXt,Date)){
date.posix-as.POSIXlt(Y)
Y-as.numeric(format(date.posix,%Y))
M-as.numeric(format(date.posix,%m))
D-as.numeric(format(date.posix,%d))
 }


 LY- (Y%%4==0  !(Y%%100==0))|(Y%%400==0)
 LY.prev- ((Y-1)%%4==0  !((Y-1)%%100==0))|((Y-1)%%400==0)
 date.yday-date.posix$yday+1
 jan1.wday-strptime(paste(Y,01-01,sep=-),%Y-%m-%d)$wday
 jan1.wday-ifelse(jan1.wday==0,7,jan1.wday)
 date.wday-date.posix$wday
 date.wday-ifelse(date.wday==0,7,date.wday)


 If the date is in the beginning, or end of the year,
 ### does it fall into a week of the previous or next year?
 Yn-ifelse(date.yday=(8-jan1.wday)jan1.wday4,Y-1,Y)
 Yn-ifelse(Yn==Y((365+LY-date.yday)(4-date.wday)),Y+1,Y)

 ##Set the week differently if the date is in the beginning,middle or
end of the year

 Wn-ifelse(
 Yn==Y-1,
 ifelse((jan1.wday==5|(jan1.wday==6 LY.prev)),53,52),
 ifelse(Yn==Y+1,1,(date.yday+(7-date.wday)+(jan1.wday-1))/7-(jan1.wday4))
 )
   return(list(Year=Yn,ISOWeek=Wn))
}


--
Gustaf Rydevik, M.Sci.
tel: +46(0)703 051 451
address:Essingetorget 40,112 66 Stockholm, SE
skype:gustaf_rydevik



--
Brian D. Ripley,  [EMAIL PROTECTED]
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax:  +44 1865 272595



--
Brian D. Ripley,  [EMAIL PROTECTED]
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax:  +44 1865 272595

__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] getting ISO week

2008-12-11 Thread Gabor Grothendieck
format(d, %U) and format(d, %W) give week numbers using
different conventions.  See ?strptime

On Thu, Dec 11, 2008 at 7:43 AM, Gustaf Rydevik
[EMAIL PROTECTED] wrote:
 Hi all,

 Is there a simple function already implemented for getting the ISO
 weeks of a Date object?
 I couldn't find one, and so wrote my own function to do it, but would
 appreciate a pointer to the default way. If a function is not yet
 implemented, could the code below be of interest to submit to CRAN?

 Best Regards,

 Gustaf

 

 getweek-function(Y,M=NULL,D=NULL){

  if(!class(Y)[1]%in%c(Date,POSIXt)) {
  date.posix-strptime(paste(c(Y,M,D),collapse=-),%Y-%m-%d)
  }
  if(class(Y)[1]%in%c(POSIXt,Date)){
 date.posix-as.POSIXlt(Y)
 Y-as.numeric(format(date.posix,%Y))
 M-as.numeric(format(date.posix,%m))
 D-as.numeric(format(date.posix,%d))
  }


  LY- (Y%%4==0  !(Y%%100==0))|(Y%%400==0)
  LY.prev- ((Y-1)%%4==0  !((Y-1)%%100==0))|((Y-1)%%400==0)
  date.yday-date.posix$yday+1
  jan1.wday-strptime(paste(Y,01-01,sep=-),%Y-%m-%d)$wday
  jan1.wday-ifelse(jan1.wday==0,7,jan1.wday)
  date.wday-date.posix$wday
  date.wday-ifelse(date.wday==0,7,date.wday)


  If the date is in the beginning, or end of the year,
  ### does it fall into a week of the previous or next year?
  Yn-ifelse(date.yday=(8-jan1.wday)jan1.wday4,Y-1,Y)
  Yn-ifelse(Yn==Y((365+LY-date.yday)(4-date.wday)),Y+1,Y)

  ##Set the week differently if the date is in the beginning,middle or
 end of the year

  Wn-ifelse(
  Yn==Y-1,
  ifelse((jan1.wday==5|(jan1.wday==6 LY.prev)),53,52),
  ifelse(Yn==Y+1,1,(date.yday+(7-date.wday)+(jan1.wday-1))/7-(jan1.wday4))
  )
return(list(Year=Yn,ISOWeek=Wn))
 }


 --
 Gustaf Rydevik, M.Sci.
 tel: +46(0)703 051 451
 address:Essingetorget 40,112 66 Stockholm, SE
 skype:gustaf_rydevik

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.


__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


Re: [R] merging data.frames columnwise (rbind with different variables, lengths)

2008-12-11 Thread David Hajage
Dear Stefan,

You could use rbind.fill() from reshape package :

 install.packages(reshape)
 library(reshape)
 df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
 df2 - data.frame(A = c(2), C = c(at home))
 rbind.fill(df1, df2)
  AB   C
1 1m at home
2 2faway
3 2 NA at home

2008/12/11 Stefan Uhmann [EMAIL PROTECTED]

 Dear List,

 I have two dataframes with overlapping colnames and want to merge them.
  Actually, what I want is more similar to rbind, but the dataframes differ
 in their columns. Here are the examples:

 df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
 df2 - data.frame(A = c(2), C = c(at home))

 Here the desired result:

  A BC
 1 1 m  at home
 2 2 f away
 3 2 NA at home

 Thanks for any help,
 Stefan

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide
 http://www.R-project.org/posting-guide.html
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Re: [R] Simplex function in R

2008-12-11 Thread Gerard M. Keogh
re pseudo inverse

On the point of generalised inverses - GINV is usually taken to mean the
moore-penrose pseudo inverse - this is the least squares projection.
There are others - e.g. the Drazin inverse which amounts to diagonalisation
- of course this inverse may not be available in R.

Gerard




   
 Gabor
 Grothendieck 
 [EMAIL PROTECTED]  To 
 ail.com  Chris Line
 Sent by:  [EMAIL PROTECTED]   
 [EMAIL PROTECTED]  cc 
 project.org   r-help@r-project.org  
   r-help@r-project.org  
   Subject 
 11/12/2008 12:14  Re: [R] Simplex function in R   
   
   
   
   
   
   




Try the pseudo inverse:

m - rbind(c(1, 1, 1), c(1, 0, 1), c(0, 1, 0))
b - c(5, 2, 3)

library(MASS)
ginv(m) %*% b


On Thu, Dec 11, 2008 at 2:20 AM, Chris Line [EMAIL PROTECTED]
wrote:
 I have a set of linear equations and would like to find any feasible
solution.  A simplex solution works in Case 1 below, but not in Case 2.  I
would be grateful for any help.

 Case 1: Find any feasible solution for the set of linear equations:
  a  +   b   +   c  = 5
  a  +   b  +  0c  = 4
 0a +   b   +   c  =  4

 Solution - a feasible (and unique) solution is a=1, b=3, c=1.

 The following R code returns a feasible solution:
 A3M = matrix(c(1,1,0,1,1,1,1,0,1),nrow=3)
 b3M = matrix(c(5,4,4),ncol=1)
 A1M = matrix(c(1,0,0,0,1,0,0,0,1),nrow=3)
 b1M = matrix(c(10,10,10),ncol=1)
 AM = matrix(c(1,1,1),nrow=1)
 simplex(a = AM, A1 = A1M, b1 = b1M, A2 = NULL, b2 = NULL, A3 = A3M, b3 =
b3M, maxi = TRUE)


 Case 2: Find any feasible solution for the set of linear equations
   a +   b   +   c  = 5
   a + 0b  +   c  = 2
 0a +   b   + 0c  = 3

 Solution - one feasible solution of many is a=1, b=3, c=1.  There are
infinite possible solutions in Case 2.

 However, the following R code fails to return any feasible solution:
 A3M = matrix(c(1,1,0,1,0,1,1,1,0),nrow=3)
 b3M = matrix(c(5,2,3),ncol=1)
 A1M = matrix(c(1,0,0,0,1,0,0,0,1),nrow=3)
 b1M = matrix(c(10,10,10),ncol=1)
 AM = matrix(c(1,1,1),nrow=1)
 simplex(a = AM, A1 = A1M, b1 = b1M, A2 = NULL, b2 = NULL, A3 = A3M, b3 =
b3M, maxi = TRUE)

 The code returns the error:
 Error in A.out[, basic] - iden(M) : subscript out of bounds

 Am I using the Simplex function incorrectly?  There may be a better way
to approach the problem of finding a feasible solution.

 Cheers,
 Chris.

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[R] Property of cov(x) - matrix, some elements of x missing

2008-12-11 Thread Lukas Gudmundsson
Dear List Members,

this question is not directly related to R but follows up a comment in
the documentation of 'cov'. In the case of missing values in the input
matrix 'x' there are various options specified via the parameter
'use'.  One of them being 'pairwise.complete.obs'. In the 'Details'
section it is mentioned that this may result in covariance matrices
that are not positive semi-definite. I assume that this is a well
known property, however I have not been successful in finding suitable
literature in explaining/documenting this phenomenon. If some one of
you could give me a hint i would be very grateful.

Best, Lukas

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Re: [R] A package to set up a questionnaire enter data

2008-12-11 Thread cryan
Not an R package, but EpiData is free software designed to to exactly this. 
It's a wonderful piece of software.  Define fields, add annotations, provide 
defaults, provide allowable values or ranges, calculate one field based on 
entry to another, conditional skipping from one question to another depending 
on answer, relational database capaability, double-entry verification, and 
more. I don't think it exports directly to Rdata format, but it can export to 
plain text, SAS, Stata, dBase, and Excel, any of which I think can be read into 
R.

--Chris Ryan

 Original message 
Date: Thu, 11 Dec 2008 12:51:10 +0100
From: David Croll [EMAIL PROTECTED]  
Subject: Re: [R] A package to set up a questionnaire  enter data  
To: r-help@r-project.org



Hello,

For entering data alone, you would not need a package. For simple 
questionnaires, you could write a function.

It could go like this. For example you want to record people's names and 
their ages:

# Sets up an empty database
database - c()

enter_data - function() {
show(Enter name:)
name - as.character(readline())
   
show(Enter age:)
age - as.numeric(readline())
   
# Appends data from one questionnaire to the
# database
database - rbind(database,data.frame(name,age))
   
# Calls the function in order to proceed
# with another questionnaire
   
enter_data()
   
# stop the function using the stop button when you are finished
}

exporting database into a CSV or a text file should not be a problem 
with write.csv() or write.csv2().



Kind regards,


David Croll

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Re: [R] ref card for data manipulation?

2008-12-11 Thread baptiste auguie

Hi,

Good idea, what do you say we try and write a page on this in the R  
wiki?


I started the topic:
http://wiki.r-project.org/rwiki/doku.php?id=guides:overview-data-manip

Once the content is there, it wouldn't be much of an effort to create  
a reference-card format if required.


Best wishes,

baptiste


On 11 Dec 2008, at 12:38, Vitalie Spinu wrote:

On Wed, 10 Dec 2008 18:29:43 +0100, Peter Dalgaard [EMAIL PROTECTED] 
 wrote:




You (as many before you) have overlooked the ave() function, which  
can

replace the ordering as well the do.call(c,tapply())



Majority of questions on this list concern data manipulation. Many  
are repetitive. Overlooking like that will always happen unless  
some comprehensive data manipulation documentation is made.
I think many people would benefit if  a specialized data.manip  
ref.card were conceived.


Tom Short's card is an excellent one but it does not cover high  
level packages like plyr, reshape, DoBy, and a few base data.manip  
functions are not there as well.


Vitalie.



_

Baptiste Auguié

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

Phone: +44 1392 264187

http://newton.ex.ac.uk/research/emag

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[R] how to get the CDF of a density() estimation?

2008-12-11 Thread Viktor Nagy
Hi,

I've estimated a simple kernel density of a univariate variable with
density(), but after I would like to find out the CDF at specific
values.
How can I do it?

thanks for your help, with it I am very close to finish my first
little bit more serious work in R,
Viktor

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Re: [R] how to get the CDF of a density() estimation?

2008-12-11 Thread Adelchi Azzalini
On Thu, 11 Dec 2008 14:28:31 +0100, Viktor Nagy wrote:

VN Hi,
VN 
VN I've estimated a simple kernel density of a univariate variable with
VN density(), but after I would like to find out the CDF at specific
VN values.
VN How can I do it?
VN 

Answer 1.
Use approfun to interpolate the outcome from density() and then 
use integrate(). The following lines show a *crude* coding of this
idea:

R x- rnorm(200)
R pdf- density(x)
R f- approxfun(pdf$x, pdf$y, yleft=0, yright=0)
R cdf-integrate(f, -Inf, 2)  # replace '2' by any other value.

Answer 2.
Do not integrate the estimated density, since this is not the most
efficient estimate of the underlying CDF. Instead, smooth the empirical
distribution function, using a smaller bandwidth of the kernel. The
optimal bandwith for kernel density estimation is of order 0(n^{-1/5}),
while for CDF estimation is O(n^{-1/3}), if n denotes the sample size.

In practical terms you can still use density(), as indicated above, but
selecting a suitably smaller bandwith compared to the one used for
density estimation.


Best wishes

Adelchi Azzalini
-- 
Adelchi Azzalini  [EMAIL PROTECTED]
Dipart.Scienze Statistiche, Università di Padova, Italia
tel. +39 049 8274147,  http://azzalini.stat.unipd.it/

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Re: [R] Logical inconsistency

2008-12-11 Thread Bernardo Rangel Tura

Hi Kenn,

Well I think your use or round isn't optimal solution. If you using 

round(x,1)-round(x,1) you create 2 problems

First: error propagation because you make 2 round.

Second: you don't using guard digits approach.

The optimal use of round is using in last calculation:

Look this

 round(8.8,1)-round(7.8,1)1
[1] TRUE
 round(8.8-7.8,1)1
[1] FALSE
 round(8.8-7.8,1)==1
[1] TRUE

Bernardo Rangel Tura, M.D,MPH,Ph.D
National Institute of Cardiology
Brazil

-- Original Message ---
From: Kenn Konstabel [EMAIL PROTECTED]
To: emma jane [EMAIL PROTECTED]
Cc: R help [EMAIL PROTECTED]
Sent: Thu, 11 Dec 2008 11:53:01 +0200
Subject: Re: [R] Logical inconsistency

 Rounding can do no good because
 
 round(8.8,1)-round(7.8,1)1
 # still TRUE
 round(8.8)-round(7.7)1
 # FALSE
 
 What you might do is compute a-b-1 and compare it to a very small number:
 
 (8.8-7.8-1)  1e-10
 # TRUE
 
 K
 
 On Wed, Dec 10, 2008 at 11:47 AM, emma jane [EMAIL PROTECTED] 
 wrote:
 
  Thanks Greg, that does make sense.  And I've solved the problem by
  rounding the variables before taking the difference between them.
 
  Thanks to all who replied.
 
  Emma JaneÂ
 
 
 
 
  
  From: Greg Snow [EMAIL PROTECTED]
 
  .com.br; Wacek Kusnierczyk [EMAIL PROTECTED]; Chuck
  Cleland [EMAIL PROTECTED]
  Cc: R help [EMAIL PROTECTED]
  Sent: Tuesday, 9 December, 2008 16:30:08
  Subject: RE: [R] Logical inconsistency
 
  Some (possibly all) of those numbers cannot be represented exactly, so
  there is a chance of round off error whenever you do some arithmetic,
  sometimes the errors cancel out, sometimes they don't.  Consider:
 
   print(8.3-7.3, digits=20)
  [1] 1.001
   print(11.3-10.3, digits=20)
  [1] 1
 
  So in the first case the rounding error gives a value that is slightly
  greater than 1, so the greater than test returns true (if you round the
  result before comparing to 1, then it will return false).  In the second
  case the uncertainties cancelled out so that you get exactly 1 which is not
  greater than 1 an so the comparison returns false.
 
  Hope this helps,
 
  --
  Gregory (Greg) L. Snow Ph.D.
  Statistical Data Center
  Intermountain Healthcare
  [EMAIL PROTECTED]
  801.408.8111
 
 
   -Original Message-
   From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
   project.org] On Behalf Of emma jane
   Sent: Tuesday, December 09, 2008 7:02 AM
   To: Bernardo Rangel Tura; Wacek Kusnierczyk; Chuck Cleland
   Cc: R help
   Subject: Re: [R] Logical inconsistency
  
   Many thanks for your help, perhaps I should have set my query in
   context  !
  
   I'm simply calculating an indicator variable [0,1] based on the whether
   the difference between two measured variables is  1 or =1.
  
   I understand the FAQ about floating point arithmetic, but am still
   puzzled that it only apparently applies to certain elements, as
   follows:
  
   8.8 - 7.8  1
TRUE
  
   8.3 - 7.3  1
TRUE
  
   However,
  
   10.2 - 9.2  1
   FALSE
  
   11.3 - 10.31
   Â FALSE
  
   Emma Jane
  
  
  
  
   
   From: Bernardo Rangel Tura [EMAIL PROTECTED]
   To: Wacek Kusnierczyk [EMAIL PROTECTED]
   Cc: R help [EMAIL PROTECTED]
   Sent: Saturday, 6 December, 2008 10:00:48
   Subject: Re: [R] Logical inconsistency
  
   On Fri, 2008-12-05 at 14:18 +0100, Wacek Kusnierczyk wrote:
Berwin A Turlach wrote:
 Dear Emma,

 On Fri, 5 Dec 2008 04:23:53 -0800 (PST)
  


 Please could someone kindly explain the following inconsistencies
 I've discovered__when performing logical calculations in R:

 8.8 - 7.8  1

 TRUE

 8.3 - 7.3  1

 TRUE


 Gladly:Â  FAQ 7.31
 http://cran.at.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-
   th
 ink-these-numbers-are-equal_003f


   
well, this answer the question only partially.  this explains why a
system with finite precision arithmetic, such as r, will fail to be
logically correct in certain cases.  it does not explain why r, a
language said to isolate a user from the underlying implementational
choices, would have to fail this way.
   
there is, in principle, no problem in having a high-level language
perform the computation in a logically consistent way.  for example,
bc is an arbitrary precision calculator language, and has no
   problem
with examples as the above:
   
bc  8.8 - 7.8  1
# 0, meaning 'no'
   
bc  8.3 - 7.3  1
# 0, meaning 'no'
   
bc  8.8 - 7.8 == 1
# 1, meaning 'yes'
   
   
the fact that r (and many others, including matlab and sage, perhaps
not
mathematica) does not perform logically here is a consequence of its
implementation of floating point arithmetic.
   
the faq you were pointed to, and its referring to the goldberg's
article, show that r does not successfully isolate a user from
   details
of the 

Re: [R] ref card for data manipulation?

2008-12-11 Thread Vitalie Spinu


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Re: [R] ref card for data manipulation?

2008-12-11 Thread hadley wickham
 You (as many before you) have overlooked the ave() function, which can
 replace the ordering as well the do.call(c,tapply())


 Majority of questions on this list concern data manipulation. Many are
 repetitive. Overlooking like that will always happen unless some
 comprehensive data manipulation documentation is made.
 I think many people would benefit if  a specialized data.manip ref.card were
 conceived.

I like the idea, but is a reference card really enough?  To me, what
most people need to tackle data manipulation problems is a broad
strategy, not a list of useful functions.  plyr is a codification of
my most recent ideas on one such strategy: splitting a big data
structure into smaller pieces, applying a function to each piece and
then joining them back together.  Just recognising your problem can be
solved with this strategy is a big step forward, the functions in plyr
just save you some typing and a bit of thought compared to doing it in
base R.

Recognising this strategy has helped me in my own data manipulation
problems - many tasks with which I used to struggle are now easy to
solve, not just because of plyr, but because I have a framework in
which to think about the problem.  But this is just one strategy and
there must be many more common strategies waiting to be identified.  I
think working on this would be time better spent - describing a
strategy gives people the tools to help themselves.  (Of course this
doesn't help the people who just want canned answers, but I'm less
interested in helping them)

Hadley

-- 
http://had.co.nz/

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Re: [R] how to get the CDF of a density() estimation?

2008-12-11 Thread Adelchi Azzalini
On Thu, 11 Dec 2008 15:11:06 +0100, Adelchi Azzalini wrote:

AA 
AA In practical terms you can still use density(), as indicated above, but
AA selecting a suitably smaller bandwith compared to the one used for
AA density estimation.

PS. 
of course this is numerically most inefficient...
Adelchi Azzalini
-- 
Adelchi Azzalini  [EMAIL PROTECTED]
Dipart.Scienze Statistiche, Università di Padova, Italia
tel. +39 049 8274147,  http://azzalini.stat.unipd.it/

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Re: [R] Principal Component Analysis - Selecting components? + right choice?

2008-12-11 Thread S Ellison
If you're intending to create a model using PCs as predictors, select
the PCs based on whether they contribute significanctly to the model
fit.

In chemometrics (multivariate stats in chemistry, among other things),
if we're expecting 3 or 4 PC's to be useful in a principal component
regression, we'd generally start with at least the first half-dozen or
so and let the model fit sort them out.

The reason for not preselecting too rigorously early on is that there's
no guarantee at all that the first couple of PC's are good predictors
for what you're interested in. The're properties of the predictor set,
not of the response set.

Mind you, there used to be something of a gap between chemometrics and
proper statistics; I'm sure chemometricians used to do things with data
that would turn a statistician pale. 

You could also look for a PLS model, which (if I recall correctly)
actually uses the response data to select the latent variables used for
prediction.

S

 Corrado [EMAIL PROTECTED] 11/12/2008 11:46:37 
Dear R gurus,

I have some climatic data for a region of the world. They are monthly
averages 
1950 -2000 of precipitation (12 months), minimum temperature (12
months), 
maximum temperature (12 months). I have scaled them to 2 km x 2km
cells, and 
I have around 75,000 cells.

I need to feed them into a statistical model as co-variates, to use
them to 
predict a response variable.

The climatic data are obviously correlated: precipitation for January
is 
correlated to precipitation for February and so on  even
precipitation 
and temperature are heavily correlated. I did some correlation analysis
and 
they are all strongly correlated.

I though of running PCA on them, in order to reduce the number of
co-variates 
I feed into the model.

I run the PCA using prcomp, quite successfully. Now I need to use a
criteria 
to select the right number of PC. (that is: is it 1,2,3,4?)

What criteria would you suggest?

At the moment, I am using a criteria based on threshold, but that is
highly 
subjective, even if there are some rules of thumb (Jolliffe,Principal 
Component Analysis, II Edition, Springer Verlag,2002). 

Could you suggest something more rigorous?

By the way, do you think I would have been better off by using
something 
different from PCA?

Best,
-- 
Corrado Topi

Global Climate Change  Biodiversity Indicators
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: [EMAIL PROTECTED] 

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Re: [R] R and Scheme

2008-12-11 Thread Wacek Kusnierczyk
Peter Dalgaard wrote:
 Wacek Kusnierczyk wrote:
 Peter Dalgaard wrote:
 Johannes Huesing wrote:
 Stavros Macrakis [EMAIL PROTECTED] [Wed, Dec 10, 2008 at
 04:59:25AM CET]:
 So I conclude that what is really meant by R semantics are based on
 Scheme
 semantics is R has functions as first-class citizens and a correct
 implementation of lexical scope, including upwards funarg.

 One other thing reminiscient of Lisp is the infix notation (as in
 +(1, 3)), which the authors have sprinkled with enough syntactic
 sugar that the users
 needn't be bothered with. To the benefit of ubiquity, I'd think.

 That's prefix notation, infix is 1+3 (and postfix is 1,3,+ as in
 old HP calculators). But you're right that R has Lisp-like parse trees
 with a thin layer of syntactic sugar:

 Lisp writes function calls as (f x y) for f(x,y) and (+ 1 3) for 1+3.
 In R we have

 e - quote(f(x,y))
 e[[1]];e[[2]]; e[[3]]
 f
 x
 y
 e - quote(1+3)
 e[[1]];e[[2]]; e[[3]]
 `+`
 [1] 1
 [1] 3


 the reminiscence is limited, though.  the following won't do:

 `+`(1,2,3)

 and

 quote(1+2+3)

 is not a list of `+`, 1, 2, and 3.

 vQ

 Essentially irrelevant. You have to distinguish between form and
 function, and it is not important that the two languages contain
 slightly different definitions and semantics of particular functions.
 The point is that the general _form_ of the parse tree is the same.

and what does the form of the syntax tree have to do with
lisp-likeness?  in java, c, etc., the string 1 + 2 + 3 would be parsed
into a tree that has the same shape as in the case of r:  a '+' in the
root, '1' in one branch, and in the other branch a tree with a '+' as
the root and '2' and '3' in the branches. 
The point is that the general _form_ of the parse tree is the same. --
does it make java or c resemble lisp?

 Because of the syntactic sugar, R does not have `+` equivalent to
 `sum` like LISP does. `+` is a binary (or unary) operator and 1+2+3
 parses as LISPs

 (+ (+ 1 2) 3).

the point is, it's not a problem of the binary-ness of the particular
function `+`.  it's that an expression where the same operator is used
infix more than once in a row is parsed and evaluated as a nested
sequence of calls, not as a single call with multiple arguments:

`%+%` = function(a, b, c=0) { print (c(a,b,c)); a+b+c }
1 %+% 2 %+% 3
`%+%`(1,2,3)


vQ

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Re: [R] repeated searching of no-missing values

2008-12-11 Thread Patrizio Frederic
dear Hadley and Bert,
thank you very much for your suggestions. I asked one question and I
learned 2 things:

1. Hadley,

library(plyr)
ddply(data, .(V1), colwise(cl))

that is exactly what I was searching for.

2. Bert,

 ?tapply says that the first argument is an **atomic** vector. A
 factor is not an atomic vector. So tapply interprets it as such by looking
 only at its representation, which is as integer values.

I admit I payed not enough attention to the definition of **atomic** vector.
That implies a deeper understanding of structures of data. I'm working with!

Many thanks,

Patrizio

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Re: [R] call lattice function in a function passing

2008-12-11 Thread Ryan Hafen
 
 If however I wanted to call the function densityplot within a function and 
 pass the groups argument as an argument of that function, how would I have 
 to proceed? It is not as straightforward as
 
 f - function(data, groupvar) {
   densityplot(~ x, data, groups = groupvar)
 }
 
 probably because the lattice function densityplot.formula preprocesses 
 the groups argument with
 
 groups - eval(substitute(groups), data, environment(formula))
 
 It there a way how I could pass the groups argument in the function f?

Here's one approach.  Pass the 'groups' variable as a character, then find 
that variable in the data frame and rename it.

d - data.frame(x = rnorm(100), y = c(a, b))

f - function(data, groupvar) {
names(data)[which(names(data) == groupvar)] - gp
densityplot(~ x, data, groups = gp)
}

f(d, groupvar=y)

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Re: [R] Validity of GLM using Gaussian family with sqrt link

2008-12-11 Thread Lam, Tzeng Yih
Dear Prof. Ripley,

Thank you for your quick response.

(A) 
 link-sqrt is a name and not accepted.  link=sqrt is a literal character 
 string, and is.

I am not entirely sure whether I understand that statement but this is what I 
found out. If I specify family=gaussian(link=sqrt), the glm() fails to run 
because it is not a default link (so, I understand this part). Following 
Venables and Ripley (2002):

 summary(glm(cnt~herbc+herbht,data=sotr,family=gaussian(link=sqrt),start=c(0.1,-0.004,0.01)))
Call:
glm(formula = cnt ~ herbc + herbht, family = gaussian(link = sqrt), 
data = sotr, start = c(0.1, -0.004, 0.01))

Coefficients:
 Estimate Std. Error t value Pr(|t|)
(Intercept)  0.462211   0.043475  10.632   2e-16 ***
herbc   -0.003315   0.001661  -1.996   0.0461 *  
herbht   0.010241   0.001291   7.935 4.86e-15 ***

AIC: 3235.0

 summary(glm(cnt~herbc+herbht,data=sotr,family=quasi(link=power(0.5),variance=constant),start=c(0.1,-0.004,0.01)))
Call:
glm(formula = cnt ~ herbc + herbht, family = quasi(link = power(0.5)), 
data = sotr, start = c(0.1, -0.004, 0.01))

Coefficients:
 Estimate Std. Error t value Pr(|t|)
(Intercept)  0.462211   0.043475  10.632   2e-16 ***
herbc   -0.003315   0.001661  -1.996   0.0461 *  
herbht   0.010241   0.001291   7.935 4.86e-15 ***

AIC: NA

Notice that the parameter estimates and corresponding standard errors are 
identical. So, my interpretation is that family=gaussian(link=sqrt) is 
identical as specify family=quasi(link=power(0.5)) in glm(). The exception is 
that AIC (and thus maximized log-likelihood values) can be computed for 
family=gaussian(link=sqrt). 

The questions are:
(A.1) Is this interpretation correct?
(A.2) If (A.1) is true, does family=gaussian(link=sqrt) implies that I am 
doing a Generalized Linear Model with normal distribution and the link function 
is: sqrt(mu) = b0+b1(herbc)+b2(herbht)?

(B)
 In less technical terms, in model 1 you compute the likelihood from 
 probabilities 
 and in model 2 from probability densities, and the latter depend on the 
 units of measurement.
Yes, you are correct and I understand it now. Although not as common these 
days, some small mammal studies still use sqrt transformation of count as 
response variable and carry out a linear model fitting with predictors (via 
least squares). So, the exercise that I got into is to compare performances of 
linear model with sqrt transformation of count and GLM with Poisson. However, 
knowing that we can't compare logLik or AIC based on different measures of 
responses. So, I thought that comparison under GLM framework might be an 
approach closer to the intention.

Thank again for your quick respond and advices. I appreciate it very much.

Best regards,
TzengYih Lam

---
Ph.D. student 
College of Forestry
Oregon State University


-Original Message-
From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
Sent: Wed 12/10/2008 11:45 PM
To: Lam, Tzeng Yih
Cc: r-help@r-project.org
Subject: Re: [R] Validity of GLM using Gaussian family with sqrt link

a) There is a difference between link=sqrt and link=sqrt.

 link: a specification for the model link function.  This can be a
   name/expression, a literal character string, a length-one
   character vector or an object of class 'link-glm' (such as
   generated by 'make.link') provided it is not specified _via_
   one of the standard names given next.

link-sqrt is a name and not accepted.  link=sqrt is a literal character
string, and is.

b) Your first model is a model for integer observations, the second for 
continuous observations.  As such, the log-likleihoods are computed with 
respect to different reference measures and are not comparable.  In less 
technical terms, in model 1 you compute the likelihood from probabilities
and in model 2 from probability densities, and the latter depend on the 
units of measurement.


On Wed, 10 Dec 2008, Lam, Tzeng Yih wrote:

 Dear all,

 I have the following dataset: each row corresponds to count of forest floor 
 small mammal captured in a plot and vegetation characteristics measured at 
 that plot

 sotr
 plot cnt herbc herbht
 1 1A1   0 37.08  53.54
 2 1A3   1 36.27  26.67
 3 1A5   0 32.50  30.62
 4 1A7   0 56.54  45.63
 5 1B2   0 41.66  38.13
 6 1B4   0 32.08  37.79
 7 1B6   0 33.71  30.62
 ...

 I am interested in comparing fit of different specification of 
 Generalized Linear Models (although there are some issues with using AIC
 or BIC for comparison, but this is the question that I like to post 
 here). Here are two of the several models that I am interested in:

 (1) Poission log-linear model
 pois-glm(cnt~herbc+herbht,family=poisson,data=sotr)
 summary(pois)
 Call:
 glm(formula = cnt ~ herbc + herbht, family = poisson, data = sotr)

 Coefficients:
 Estimate Std. Error z value Pr(|z|)
 (Intercept) -1.341254   0.089969 

Re: [R] Logical inconsistency

2008-12-11 Thread Kenn Konstabel
Hi,

I agree -- and my examples using round were meant as bad and dangerous
examples. Using round at the last step is better and may solve the problem,
but in your example ...

 round(8.8-7.8,1)==1
[1] TRUE

... you have to know in advance how many decimal places can possibly make a
difference (is it just one? maybe it is 2? 3? 15?).

 round(8.8-7.8,14)==1
[1] TRUE
 round(8.8-7.8,15)==1
[1] FALSE

... or, equivalently,

 8.8-7.8-1  1e-15
[1] TRUE
 8.8-7.8-1  1e-16
[1] FALSE

Best regards,
Kenn

On Thu, Dec 11, 2008 at 4:18 PM, Bernardo Rangel Tura
[EMAIL PROTECTED]wrote:


 Hi Kenn,

 Well I think your use or round isn't optimal solution. If you using

 round(x,1)-round(x,1) you create 2 problems

 First: error propagation because you make 2 round.

 Second: you don't using guard digits approach.

 The optimal use of round is using in last calculation:

 Look this

  round(8.8,1)-round(7.8,1)1
 [1] TRUE
  round(8.8-7.8,1)1
 [1] FALSE
  round(8.8-7.8,1)==1
 [1] TRUE

 Bernardo Rangel Tura, M.D,MPH,Ph.D
 National Institute of Cardiology
 Brazil

 -- Original Message ---
 From: Kenn Konstabel [EMAIL PROTECTED]
 To: emma jane [EMAIL PROTECTED]
 Cc: R help [EMAIL PROTECTED]
 Sent: Thu, 11 Dec 2008 11:53:01 +0200
 Subject: Re: [R] Logical inconsistency

  Rounding can do no good because
 
  round(8.8,1)-round(7.8,1)1
  # still TRUE
  round(8.8)-round(7.7)1
  # FALSE
 
  What you might do is compute a-b-1 and compare it to a very small number:
 
  (8.8-7.8-1)  1e-10
  # TRUE
 
  K
 
  On Wed, Dec 10, 2008 at 11:47 AM, emma jane [EMAIL PROTECTED]
  wrote:
 
   Thanks Greg, that does make sense.  And I've solved the problem by
   rounding the variables before taking the difference between them.
  
   Thanks to all who replied.
  
   Emma JaneÂ
  
  
  
  
   
   From: Greg Snow [EMAIL PROTECTED]
  
   .com.br; Wacek Kusnierczyk [EMAIL PROTECTED];
 Chuck
   Cleland [EMAIL PROTECTED]
   Cc: R help [EMAIL PROTECTED]
   Sent: Tuesday, 9 December, 2008 16:30:08
   Subject: RE: [R] Logical inconsistency
  
   Some (possibly all) of those numbers cannot be represented exactly, so
   there is a chance of round off error whenever you do some arithmetic,
   sometimes the errors cancel out, sometimes they don't.  Consider:
  
print(8.3-7.3, digits=20)
   [1] 1.001
print(11.3-10.3, digits=20)
   [1] 1
  
   So in the first case the rounding error gives a value that is slightly
   greater than 1, so the greater than test returns true (if you round the
   result before comparing to 1, then it will return false).  In the
 second
   case the uncertainties cancelled out so that you get exactly 1 which is
 not
   greater than 1 an so the comparison returns false.
  
   Hope this helps,
  
   --
   Gregory (Greg) L. Snow Ph.D.
   Statistical Data Center
   Intermountain Healthcare
   [EMAIL PROTECTED]
   801.408.8111
  
  
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
project.org] On Behalf Of emma jane
Sent: Tuesday, December 09, 2008 7:02 AM
To: Bernardo Rangel Tura; Wacek Kusnierczyk; Chuck Cleland
Cc: R help
Subject: Re: [R] Logical inconsistency
   
Many thanks for your help, perhaps I should have set my query in
context  !
   
I'm simply calculating an indicator variable [0,1] based on the
 whether
the difference between two measured variables is  1 or =1.
   
I understand the FAQ about floating point arithmetic, but am still
puzzled that it only apparently applies to certain elements, as
follows:
   
8.8 - 7.8  1
 TRUE
   
8.3 - 7.3  1
 TRUE
   
However,
   
10.2 - 9.2  1
FALSE
   
11.3 - 10.31
 FALSE
   
Emma Jane
   
   
   
   

From: Bernardo Rangel Tura [EMAIL PROTECTED]
To: Wacek Kusnierczyk [EMAIL PROTECTED]
Cc: R help [EMAIL PROTECTED]
Sent: Saturday, 6 December, 2008 10:00:48
Subject: Re: [R] Logical inconsistency
   
On Fri, 2008-12-05 at 14:18 +0100, Wacek Kusnierczyk wrote:
 Berwin A Turlach wrote:
  Dear Emma,
 
  On Fri, 5 Dec 2008 04:23:53 -0800 (PST)
   
 
 
  Please could someone kindly explain the following
 inconsistencies
  I've discovered__when performing logical calculations in R:
 
  8.8 - 7.8  1
 
  TRUE
 
  8.3 - 7.3  1
 
  TRUE
 
 
  Gladly:Â  FAQ 7.31
 
 http://cran.at.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-
th
  ink-these-numbers-are-equal_003f
 
 

 well, this answer the question only partially.  this explains why
 a
 system with finite precision arithmetic, such as r, will fail to be
 logically correct in certain cases.  it does not explain why r, a
 language said to isolate a user from the underlying
 implementational
 choices, would have to fail this way.

 there is, in principle, no problem 

[R] Sorting problem

2008-12-11 Thread ronggui
Sys.setlocale(,C)
x1 - as.character(date()) # I use date to record the time, and save
it to sqlite database, to it converted to character
x1_2 - strptime(x1, %a %b %d %H:%M:%S %Y)

x2 - as.character(date())
x2_2 - strptime(x2, %a %b %d %H:%M:%S %Y)

X-c(x1_2,x2_2)

order(X)  ## I want to get the permutation other than the sorted vector.
## order(X) works in windows but not Linux.

any alternative way to the the permutation?

-- 
HUANG Ronggui, Wincent
Tel: (00852) 3442 3832
PhD Candidate, City University of Hong Kong
Website: http://ronggui.huang.googlepages.com/
RQDA project: http://rqda.r-forge.r-project.org/

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[R] Combining tplot and barplot

2008-12-11 Thread mmichel

Hello!

I am pretty new to R statistics and trying to figure out how to show  
the barplot and the single data points in one single plot.
I am using the tplot code from the following site for showing the  
single datapoints:
http://biostat.mc.vanderbilt.edu/twiki/pub/Main/TatsukiRcode/ 
TatsukiRcodeTplot.r


I have two sets of data (x,y) that I want to compare, by plotting a  
Barplot and the single data points. Unfortunately they are shifted,  
so that the data points are not right on top of the bars.


The code I used for plotting the data:

x-c(835,728,2281,1049,1574,1340,621)
y-c(466,922,2647,914,1342,998,655)
aver-c(mean(x),mean(y))
barplot(aver,col=0,ylim=range(0,2750))
tplot(x,y,add=TRUE,axes=FALSE)

I would be grateful, if someone could tell me, what the problem (and  
hopefully the solution) might be!


Thank you very much!

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Re: [R] tapply within a data.frame: a simpler alternative?

2008-12-11 Thread David Freedman

You might take a look at the transformBy function in the doBy package

For example, 
new.df=transformBy(~group,data=my.df, new=y/max(y))

David Freedman


baptiste auguie-2 wrote:
 
 Dear list,
 
 I have a data.frame with x, y values and a 3-level factor group,  
 say. I want to create a new column in this data.frame with the values  
 of y scaled to 1 by group. Perhaps the example below describes it best:
 
 x - seq(0, 10, len=100)
 my.df - data.frame(x = rep(x, 3), y=c(3*sin(x), 2*cos(x),  
 cos(2*x)), # note how the y values have a different maximum  
 depending on the group
  group = factor(rep(c(sin, cos, cos2), each=100)))
 library(reshape) 
 df.melt - melt(my.df, id=c(x,group)) # make a long format
 df.melt - df.melt[ order(df.melt$group) ,] # order the data.frame  
 by the group factor
 df.melt$norm - do.call(c, tapply(df.melt$value, df.melt$group,  
 function(.v) {.v / max(.v)})) # calculate the normalised value per  
 group and assign it to a new column
 library(lattice)
 xyplot(norm + value ~ x,groups=group,  data=df.melt, auto.key=T) #  
 check that it worked
 
 
 This procedure works, but it feels like I'm reinventing the wheel  
 using hammer and saw. I tried to use aggregate, by, ddply (plyr  
 package), but I coudn't find anything straight-forward.
 
 I'll appreciate any input,
 
 Baptiste
 
 
 
 
 
 _
 
 Baptiste Auguié
 
 School of Physics
 University of Exeter
 Stocker Road,
 Exeter, Devon,
 EX4 4QL, UK
 
 Phone: +44 1392 264187
 
 http://newton.ex.ac.uk/research/emag
 
 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide
 http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.
 
 


-
David Freedman
Atlanta
-- 
View this message in context: 
http://www.nabble.com/tapply-within-a-data.frame%3A-a-simpler-alternative--tp20939647p20958347.html
Sent from the R help mailing list archive at Nabble.com.

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[R] passing on the ... arguments in a progammed graphics function

2008-12-11 Thread Mark Heckmann
Hi everyone,

I want to write a wrapper function that uses the hist() function. Now I want
to allow the hist breaks argument as optional in my function. So when my
function contains the breaks argument I want the hist() function to use it,
if not, I want the hist() function to use its default for breaks.
How can I do that?

myFunction - function(data, ...)   # breaks= as optional here
{
hist(data, breaks=???)
}

TIA 
Mark

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Re: [R] Downloading Reuters data from R

2008-12-11 Thread Rory.WINSTON
Hi Shubha

I have created an extension DLL for downloading time series data from Reuters. 
You can download it from here:

http://www.theresearchkitchen.com/blog/archives/287

There is also a short manual available at the same location:

http://www.theresearchkitchen.com/blog/wp-content/uploads/2008/12/intro.pdf

I am currently in the process of uploading a separate extension DLL for 
retrieval of real-time data from Reuters.

Thanks
Rory


Rory Winston
RBS Global Banking  Markets
Office: +44 20 7085 4476

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Shubha 
Vishwanath Karanth
Sent: 11 December 2008 07:41
To: [EMAIL PROTECTED]
Subject: [R] Downloading Reuters data from R

Hi R,



Can we download Reuters (3000 Xtra) data from R? Does ODBC package help me in 
this? Or otherwise, is there a way to extract daily closing prices data of 
Reuters from R?





Thank you very much,

Shubha

This e-mail may contain confidential and/or privileged i...{{dropped:13}}

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***
The Royal Bank of Scotland plc. Registered in Scotland No 90312. Registered 
Office: 36 St Andrew Square, Edinburgh EH2 2YB. 
Authorised and regulated by the Financial Services Authority 

This e-mail message is confidential and for use by the=2...{{dropped:22}}

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Re: [R] Downloading Reuters data from R

2008-12-11 Thread Tony Breyal
Hi Shubha,

I'm replying offlist because although I don't have an answer to your
question, i thought i would point you in the direction of Rmetrics
(http://www.rmetrics.org/rmetricsPackages.htm) as there might be
something in there that may be helpful if you don't get a more direct
answer from your thread. Or maybe a search on r-sig-finance (https://
stat.ethz.ch/pipermail/r-sig-finance/) might bring up something
helpful to you.

Hope that helps a little bit  :-)

Tony Breyal.

On 11 Dec, 07:40, Shubha Vishwanath Karanth
[EMAIL PROTECTED] wrote:
 Hi R,

 Can we download Reuters (3000 Xtra) data from R? Does ODBC package help
 me in this? Or otherwise, is there a way to extract daily closing prices
 data of Reuters from R?

 Thank you very much,

 Shubha

 This e-mail may contain confidential and/or privileged i...{{dropped:13}}

 __
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 PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
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Re: [R] ref card for data manipulation?

2008-12-11 Thread Vitalie Spinu

On Thu, 11 Dec 2008 15:19:03 +0100, hadley wickham [EMAIL PROTECTED] wrote:


You (as many before you) have overlooked the ave() function, which can
replace the ordering as well the do.call(c,tapply())



Majority of questions on this list concern data manipulation. Many are
repetitive. Overlooking like that will always happen unless some
comprehensive data manipulation documentation is made.
I think many people would benefit if  a specialized data.manip ref.card  
were

conceived.


I like the idea, but is a reference card really enough?  To me, what
most people need to tackle data manipulation problems is a broad
strategy, not a list of useful functions. 


Absolutely agree. A list of useful strategies is an excellent idea :). A wiki page for 
discussion? May be  clipping some conceptual passages from your reshape and plyr 
documentation is a good start? And other strategy ideas will start flowing 
soon.

Vitalie.

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Re: [R] motif search

2008-12-11 Thread Jean lobry

Dear Alessia,


 I am very new to R and wanted to know if there is a package that, given very
 long nucleotide sequences, searches and identifies short (7-10nt) motifs..  I
 would like to look for enrichment of certain motifs in genomic sequences.

 I tried using MEME (not an R package, I know), but the online version only
 allows sequences up to MAX 6 nucleotides, and that's too short for my
 needs..


You may try this:

#
# Load the seqinr package:
#
  library(seqinr)
#
# A FASTA file example - that ships with seqinr - which contains
# the complete genome sequence of Chlamydia trachomatis :
#
  fastafile - system.file(sequences/ct.fasta, package = seqinr)
#
# Import the sequence as a string of characters:
#
  myseq - read.fasta(fastafile, as.string = TRUE)
  nchar(myseq) # 1042519, that is a Mb sequence
#
# Look for motif atatatat, with possible overlap:
#
  words.pos(atatatat, myseq, extended = TRUE)
#
# This returns the posistions where the motif is found, that
# is : 236501 236503 283987 687083 792792 792794
#
  substr(myseq, 236501, 236501 + 8)
#
# Should be
# [1] atatatata
#

HTH,

Jean
--
Jean R. Lobry([EMAIL PROTECTED])
Laboratoire BBE-CNRS-UMR-5558, Univ. C. Bernard - LYON I,
43 Bd 11/11/1918, F-69622 VILLEURBANNE CEDEX, FRANCE
allo  : +33 472 43 27 56 fax: +33 472 43 13 88
http://pbil.univ-lyon1.fr/members/lobry/

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Re: [R] passing on the ... arguments in a progammed graphics function

2008-12-11 Thread Duncan Murdoch

On 12/11/2008 11:01 AM, Mark Heckmann wrote:

Hi everyone,

I want to write a wrapper function that uses the hist() function. Now I want
to allow the hist breaks argument as optional in my function. So when my
function contains the breaks argument I want the hist() function to use it,
if not, I want the hist() function to use its default for breaks.
How can I do that?

myFunction - function(data, ...)   # breaks= as optional here
{
hist(data, breaks=???)
}



If you make your call as

 hist(data, ...)

then a breaks arg would be passed along (as would any other).

Duncan Murdoch

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Re: [R] Validity of GLM using Gaussian family with sqrt link

2008-12-11 Thread Gerard M. Keogh
Hi all,

Just on this question :

can I assume any R internal defined function can be used to describe the
link (e.g. = arctan) so long as its increasing and monotone?
How might abs work for example - (except at 0)?

And/or finally, can I define any old function in R called myfun and use
link=myfun provided myfun is a sort of nice function?

Gerard



   
 Lam, Tzeng Yih  
 [EMAIL PROTECTED] 
 gonstate.edu  To 
 Sent by:  Prof Brian Ripley 
 [EMAIL PROTECTED] [EMAIL PROTECTED] 
 project.orgcc 
   r-help@r-project.org
   Subject 
 11/12/2008 15:20  Re: [R] Validity of GLM using   
   Gaussian family with sqrt link  
   
   
   
   
   
   




Dear Prof. Ripley,

Thank you for your quick response.

(A)
 link-sqrt is a name and not accepted.  link=sqrt is a literal character
string, and is.

I am not entirely sure whether I understand that statement but this is what
I found out. If I specify family=gaussian(link=sqrt), the glm() fails to
run because it is not a default link (so, I understand this part).
Following Venables and Ripley (2002):


summary(glm(cnt~herbc+herbht,data=sotr,family=gaussian(link=sqrt),start=c(0.1,-0.004,0.01)))

Call:
glm(formula = cnt ~ herbc + herbht, family = gaussian(link = sqrt),
data = sotr, start = c(0.1, -0.004, 0.01))

Coefficients:
 Estimate Std. Error t value Pr(|t|)
(Intercept)  0.462211   0.043475  10.632   2e-16 ***
herbc   -0.003315   0.001661  -1.996   0.0461 *
herbht   0.010241   0.001291   7.935 4.86e-15 ***

AIC: 3235.0


summary(glm(cnt~herbc+herbht,data=sotr,family=quasi(link=power(0.5),variance=constant),start=c(0.1,-0.004,0.01)))

Call:
glm(formula = cnt ~ herbc + herbht, family = quasi(link = power(0.5)),
data = sotr, start = c(0.1, -0.004, 0.01))

Coefficients:
 Estimate Std. Error t value Pr(|t|)
(Intercept)  0.462211   0.043475  10.632   2e-16 ***
herbc   -0.003315   0.001661  -1.996   0.0461 *
herbht   0.010241   0.001291   7.935 4.86e-15 ***

AIC: NA

Notice that the parameter estimates and corresponding standard errors are
identical. So, my interpretation is that family=gaussian(link=sqrt) is
identical as specify family=quasi(link=power(0.5)) in glm(). The exception
is that AIC (and thus maximized log-likelihood values) can be computed for
family=gaussian(link=sqrt).

The questions are:
(A.1) Is this interpretation correct?
(A.2) If (A.1) is true, does family=gaussian(link=sqrt) implies that I am
doing a Generalized Linear Model with normal distribution and the link
function is: sqrt(mu) = b0+b1(herbc)+b2(herbht)?

(B)
 In less technical terms, in model 1 you compute the likelihood from
probabilities
 and in model 2 from probability densities, and the latter depend on the
 units of measurement.
Yes, you are correct and I understand it now. Although not as common these
days, some small mammal studies still use sqrt transformation of count as
response variable and carry out a linear model fitting with predictors (via
least squares). So, the exercise that I got into is to compare performances
of linear model with sqrt transformation of count and GLM with Poisson.
However, knowing that we can't compare logLik or AIC based on different
measures of responses. So, I thought that comparison under GLM framework
might be an approach closer to the intention.

Thank again for your quick respond and advices. I appreciate it very much.

Best regards,
TzengYih Lam

---
Ph.D. student
College of Forestry
Oregon State University


-Original Message-
From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
Sent: Wed 12/10/2008 11:45 PM
To: Lam, Tzeng Yih
Cc: r-help@r-project.org
Subject: Re: [R] Validity of GLM using Gaussian family with sqrt link

a) There is a difference between link=sqrt and link=sqrt.

 link: a specification for the model link function.  This can be a
   name/expression, a literal character string, a length-one
   character vector or an object of class 'link-glm' (such as
   

Re: [R] A package to set up a questionnaire enter data

2008-12-11 Thread CE.KA

Thank you


ryancw wrote:
 
 Not an R package, but EpiData is free software designed to to exactly
 this. It's a wonderful piece of software.  Define fields, add annotations,
 provide defaults, provide allowable values or ranges, calculate one field
 based on entry to another, conditional skipping from one question to
 another depending on answer, relational database capaability, double-entry
 verification, and more. I don't think it exports directly to Rdata format,
 but it can export to plain text, SAS, Stata, dBase, and Excel, any of
 which I think can be read into R.
 
 --Chris Ryan
 
  Original message 
Date: Thu, 11 Dec 2008 12:51:10 +0100
From: David Croll [EMAIL PROTECTED]  
Subject: Re: [R] A package to set up a questionnaire  enter data  
To: r-help@r-project.org



Hello,

For entering data alone, you would not need a package. For simple 
questionnaires, you could write a function.

It could go like this. For example you want to record people's names and 
their ages:

# Sets up an empty database
database - c()

enter_data - function() {
show(Enter name:)
name - as.character(readline())
   
show(Enter age:)
age - as.numeric(readline())
   
# Appends data from one questionnaire to the
# database
database - rbind(database,data.frame(name,age))
   
# Calls the function in order to proceed
# with another questionnaire
   
enter_data()
   
# stop the function using the stop button when you are finished
}

exporting database into a CSV or a text file should not be a problem 
with write.csv() or write.csv2().



Kind regards,


David Croll

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Re: [R] Sorting problem

2008-12-11 Thread ronggui
Sorry for the last post. I didn't use the latest version of R. It
works under Linux as well for R-2.8.0 patch.

Best

On Thu, Dec 11, 2008 at 11:34 PM, ronggui [EMAIL PROTECTED] wrote:
 Sys.setlocale(,C)
 x1 - as.character(date()) # I use date to record the time, and save
 it to sqlite database, to it converted to character
 x1_2 - strptime(x1, %a %b %d %H:%M:%S %Y)

 x2 - as.character(date())
 x2_2 - strptime(x2, %a %b %d %H:%M:%S %Y)

 X-c(x1_2,x2_2)

 order(X)  ## I want to get the permutation other than the sorted vector.
 ## order(X) works in windows but not Linux.

 any alternative way to the the permutation?

 --
 HUANG Ronggui, Wincent
 Tel: (00852) 3442 3832
 PhD Candidate, City University of Hong Kong
 Website: http://ronggui.huang.googlepages.com/
 RQDA project: http://rqda.r-forge.r-project.org/




-- 
HUANG Ronggui, Wincent
Tel: (00852) 3442 3832
PhD Candidate, City University of Hong Kong
Website: http://ronggui.huang.googlepages.com/
RQDA project: http://rqda.r-forge.r-project.org/

__
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Re: [R] Extracting the name of an object into a character string

2008-12-11 Thread Dimitris Rizopoulos

do you mean something like the following:

f - function (x) {
deparse(substitute(x))
}

x - 5
y - 6
z - 7

f(x)
f(y)
f(z)


I hope it helps.

Best,
Dimitris


Philip Whittall wrote:

Dear List,

I am writing a function in R with the facility to store models for later
use in scoring.
It would be very useful if I could include in the name of the file
stored the name of
the model object being stored, this name being chosen by the user in the
function
call. A simple function to store the name of an object as a character
string would fit the
bill, but I have not found one. name() doesn't appear to do what I want,
maybe I'm using
it wrongly.  Any suggestions please ? I'm running 2.8.0 on windows XP,

Thanks,

Philip
 




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Erasmus Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

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Re: [R] Validity of GLM using Gaussian family with sqrt link

2008-12-11 Thread Prof Brian Ripley

Please do read the help page: fortune(WTFM) applies.

On Thu, 11 Dec 2008, Gerard M. Keogh wrote:


Hi all,

Just on this question :

can I assume any R internal defined function can be used to describe the
link (e.g. = arctan) so long as its increasing and monotone?
How might abs work for example - (except at 0)?


No.


And/or finally, can I define any old function in R called myfun and use
link=myfun provided myfun is a sort of nice function?


No.


From the help page:


link: a specification for the model link function.  This can be a
  name/expression, a literal character string, a length-one
  character vector or an object of class 'link-glm' (such as
  generated by 'make.link') provided it is not specified _via_
  one of the standard names given next.

You have to specify a *model link function*, as in


gaussian(link=arctan)

Error in switch(link, logit = { : ‘arctan’ link not recognised

Only those known by name (to make.link) or an object of the specified 
class can be used.



Gerard




Lam, Tzeng Yih
[EMAIL PROTECTED]
gonstate.edu  To
Sent by:  Prof Brian Ripley
[EMAIL PROTECTED] [EMAIL PROTECTED]
project.orgcc
  r-help@r-project.org
  Subject
11/12/2008 15:20  Re: [R] Validity of GLM using
  Gaussian family with sqrt link










Dear Prof. Ripley,

Thank you for your quick response.

(A)

link-sqrt is a name and not accepted.  link=sqrt is a literal character

string, and is.

I am not entirely sure whether I understand that statement but this is what
I found out. If I specify family=gaussian(link=sqrt), the glm() fails to
run because it is not a default link (so, I understand this part).
Following Venables and Ripley (2002):




summary(glm(cnt~herbc+herbht,data=sotr,family=gaussian(link=sqrt),start=c(0.1,-0.004,0.01)))

Call:
glm(formula = cnt ~ herbc + herbht, family = gaussian(link = sqrt),
   data = sotr, start = c(0.1, -0.004, 0.01))

Coefficients:
Estimate Std. Error t value Pr(|t|)
(Intercept)  0.462211   0.043475  10.632   2e-16 ***
herbc   -0.003315   0.001661  -1.996   0.0461 *
herbht   0.010241   0.001291   7.935 4.86e-15 ***

AIC: 3235.0




summary(glm(cnt~herbc+herbht,data=sotr,family=quasi(link=power(0.5),variance=constant),start=c(0.1,-0.004,0.01)))

Call:
glm(formula = cnt ~ herbc + herbht, family = quasi(link = power(0.5)),
   data = sotr, start = c(0.1, -0.004, 0.01))

Coefficients:
Estimate Std. Error t value Pr(|t|)
(Intercept)  0.462211   0.043475  10.632   2e-16 ***
herbc   -0.003315   0.001661  -1.996   0.0461 *
herbht   0.010241   0.001291   7.935 4.86e-15 ***

AIC: NA

Notice that the parameter estimates and corresponding standard errors are
identical. So, my interpretation is that family=gaussian(link=sqrt) is
identical as specify family=quasi(link=power(0.5)) in glm(). The exception
is that AIC (and thus maximized log-likelihood values) can be computed for
family=gaussian(link=sqrt).

The questions are:
(A.1) Is this interpretation correct?
(A.2) If (A.1) is true, does family=gaussian(link=sqrt) implies that I am
doing a Generalized Linear Model with normal distribution and the link
function is: sqrt(mu) = b0+b1(herbc)+b2(herbht)?

(B)

In less technical terms, in model 1 you compute the likelihood from

probabilities

and in model 2 from probability densities, and the latter depend on the
units of measurement.

Yes, you are correct and I understand it now. Although not as common these
days, some small mammal studies still use sqrt transformation of count as
response variable and carry out a linear model fitting with predictors (via
least squares). So, the exercise that I got into is to compare performances
of linear model with sqrt transformation of count and GLM with Poisson.
However, knowing that we can't compare logLik or AIC based on different
measures of responses. So, I thought that comparison under GLM framework
might be an approach closer to the intention.

Thank again for your quick respond and advices. I appreciate it very much.

Best regards,
TzengYih Lam

---
Ph.D. student
College of Forestry
Oregon State University


-Original Message-
From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
Sent: Wed 12/10/2008 11:45 PM
To: Lam, Tzeng Yih
Cc: r-help@r-project.org
Subject: Re: [R] Validity of GLM using Gaussian family with sqrt link

a) There is a difference between link=sqrt and link=sqrt.

link: a specification for the model link function.  This can be a
  name/expression, a literal character string, a length-one
  character vector or an object of class 'link-glm' (such as
  

[R] very long integers

2008-12-11 Thread Aaron Robotham

A quick question really:

I have a database with extremely long integer IDs (eg  
588848900971299297), which is too big for R to cope with internally  
(it appears to store as a double), and when I do any frequency tables  
erroneous results appear. Does anyone know of a package that extends  
internal storage up to LONG, or is the only solution to read it in as  
a character from the original data?


In case anyone is curious, I didn't create the IDs, and in some form I  
must conserve all of the ID information for later use.


Thanks,

Aaron

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[R] Logical in test

2008-12-11 Thread David B. Thompson, Ph.D., P.E., D.WRE, CFM
OK, this should be trivial but I'm not finding it. I want to compress  
the test,


if (i==7 | i==10 | i==30 | i==50) {}

into something like

if (i in c(7,10,30,50)) {}

so I can build a excludes vector

excludes - c(7,10,30,50)

and test

if (i in excludes) {}

However, I'm not finding a clue on how to accomplish this, if it can  
be done. Would someone with more R experience lend a helping hand  
please? A reference (so I can continue learning) would also be  
appreciated.


Thanks...

-=d

David Thompson, Ph.D., P.E., D.WRE, CFM
Civil Engineer/Hydrologist

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[R] help with predict in stats4

2008-12-11 Thread David Kaplan

Hi,

We're using stats4 for a logistic regression.  The code is

chdreg.logit2 - glm(chd ~ age + sex, family = binomial)
summary(chdreg.logit2)
oddsratios - coef(chdreg.logit2)
exp(oddsratios)

# Calculate model predicted values
pred - predict(chdreg.logit2,type=response)

The glm part runs fine, and up to now so has the predict function.  
However, now we're getting the following error


Error in function (classes, fdef, mtable)  :
 unable to find an inherited method for function predict, for 
signature glm


Any thoughts about why this seems to now be appearing. 


Thanks in advance.


--
===
David Kaplan, Ph.D.
Professor
Department of Educational Psychology
University of Wisconsin - Madison
Educational Sciences, Room, 1061
1025 W. Johnson Street
Madison, WI 53706

email: [EMAIL PROTECTED]
homepage:
http://www.education.wisc.edu/edpsych/default.aspx?content=kaplan.html
Phone: 608-262-0836

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Re: [R] merging data.frames columnwise (rbind with different variables, lengths)

2008-12-11 Thread Dimitris Rizopoulos

have a look at merge(), e.g.,

df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
df2 - data.frame(A = c(2), C = c(at home))

merge(df1, df2, all = TRUE, sort = FALSE)


I hope it helps.

Best,
Dimitris


Stefan Uhmann wrote:

Dear List,

I have two dataframes with overlapping colnames and want to merge them. 
 Actually, what I want is more similar to rbind, but the dataframes 
differ in their columns. Here are the examples:


df1 - data.frame(A = c(1,2), B = c(m,f), C = c(at home, away))
df2 - data.frame(A = c(2), C = c(at home))

Here the desired result:

  A BC
1 1 m  at home
2 2 f away
3 2 NA at home

Thanks for any help,
Stefan

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--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

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Re: [R] very long integers

2008-12-11 Thread Rory.WINSTON
Have you looked at the R interface to gmp?

http://cran.r-project.org/web/packages/gmp/index.html


Rory Winston
RBS Global Banking  Markets
Office: +44 20 7085 4476

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Aaron Robotham
Sent: 11 December 2008 17:07
To: r-help@r-project.org
Subject: [R] very long integers

A quick question really:

I have a database with extremely long integer IDs (eg 588848900971299297), 
which is too big for R to cope with internally (it appears to store as a 
double), and when I do any frequency tables erroneous results appear. Does 
anyone know of a package that extends internal storage up to LONG, or is the 
only solution to read it in as a character from the original data?

In case anyone is curious, I didn't create the IDs, and in some form I must 
conserve all of the ID information for later use.

Thanks,

Aaron

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Re: [R] getting ISO week

2008-12-11 Thread Gustaf Rydevik
On Thu, Dec 11, 2008 at 2:10 PM, Prof Brian Ripley
[EMAIL PROTECTED] wrote:
 A slightly simpler version is

 format(Sys.Date(), %V)


 On Thu, 11 Dec 2008, Prof Brian Ripley wrote:

 strftime(x, %V)

 E.g.

 strftime(as.POSIXlt(Sys.Date()), %V)

 is 50, and you might want as.numeric() on it.

 Note that this is OS-dependent, and AFAIR Windows does not have it.


-

On Thu, Dec 11, 2008 at 2:15 PM, Gabor Grothendieck
[EMAIL PROTECTED] wrote:
 format(d, %U) and format(d, %W) give week numbers using
 different conventions.  See ?strptime


Thank you both for your replies!

I'm on windows, so prof Ripleys solution does not work (why is this
OS-dependent?).
Regarding Gabor's solution, neither convention follow the ISO 8601
standard, which is used in Europe (and Sweden in particular). See
http://en.wikipedia.org/wiki/ISO_8601#Week_dates .
So it seems that my function does fill a hole, however small

I know that for me, working with week numbers, which are used quite
heavily in Sweden, have always been a major frustration.
Would it be possible to implement something similar to my solution in
base, and how should I go about making it fit in to the rest of the
date functions?

/Gustaf



-- 
Gustaf Rydevik, M.Sci.
tel: +46(0)703 051 451
address:Essingetorget 40,112 66 Stockholm, SE
skype:gustaf_rydevik

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Re: [R] Logical in test

2008-12-11 Thread Gustavo Carvalho
Take a look at ?any.

On Thu, Dec 11, 2008 at 3:11 PM, David B. Thompson, Ph.D., P.E.,
D.WRE, CFM [EMAIL PROTECTED] wrote:
 OK, this should be trivial but I'm not finding it. I want to compress the
 test,

 if (i==7 | i==10 | i==30 | i==50) {}

 into something like

 if (i in c(7,10,30,50)) {}

 so I can build a excludes vector

 excludes - c(7,10,30,50)

 and test

 if (i in excludes) {}

 However, I'm not finding a clue on how to accomplish this, if it can be
 done. Would someone with more R experience lend a helping hand please? A
 reference (so I can continue learning) would also be appreciated.

 Thanks...

 -=d

 David Thompson, Ph.D., P.E., D.WRE, CFM
 Civil Engineer/Hydrologist

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[R] generate combination multiset (set with repetition)

2008-12-11 Thread Reuben Cummings
Hi,

This has been asked before but not sufficiently answered from what I
could find. How do you create combinations
with repetitions (multisets) in R?

If I have
 set - array(1:3)

And I want to choose all combinations of picking 2 numbers, I want to
get a print out like

 [,1] [,2]
[1,]11
[2,]12
[3,]13
[4,]22
[5,]23
[6,]33

subsets(set, 2, allow.repeat=T) should work, but I can't get the
multic package to install, t(combn(set,2)) was suggested but it
doesn't produce repetitions; expand.grid(rep(list(1:3), 2)) was also
suggested, but it produces permuations, not combinations.
Additionally, I would like to iterate through each resultant set for
large n (similar to the description for getNextSet {pcalg}). Any
suggestions?

Reuben Cummings

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[R] problem with legend

2008-12-11 Thread valeria pedrina
hi all,
I want to do a plot and put the legend on the left of y axis this is my
code:

x-seq(1980,2005,1)

plot(x,tfa_ita,type=l,col=1,xlim=c(1979,2005),ylim=c(0.2,1.7),xlab=,ylab=,main=Totale
Attivita` Finanziarie)
lines(x,tfa_spa,type=l,col=2)
lines(x,tfa_aus,type=l,col=3)
lines(x,tfa_uk,type=l,col=4)
lines(x,tfa_ger,type=l,col=5)
lines(x,tfa_usa,type=l,col=1,lty=4)
lines(x,tfa_jap,type=l,col=2,lty=4)
lines(x,tfa_can,type=l,col=3,lty=4)
lines(x,tfa_fra,type=l,col=4,lty=4)

legend(locator[1],c(ita,spa,aus,uk,ger,usa,jap,can,fra),col=c(1,2,3,4,5,1,2,3,4),lty=c(1,1,1,1,1,4,4,4,4))


when I touch the graphics to put the legend, R puts it on my lines and not
on the left of y axis

any idea? where I make a mistake?

thank you very much
Valeria

[[alternative HTML version deleted]]

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[R] very long integers

2008-12-11 Thread Aaron Robotham

A quick question really:

I have a database with extremely long integer IDs (eg  
588848900971299297), which is too big for R to cope with internally  
(it appears to store as a double), and when I do any frequency tables  
erroneous results appear. Does anyone know of a package that extends  
internal storage up to LONG, or is the only solution to read it in as  
a character from the original data?


In case anyone is curious, I didn't create the IDs, and in some form I  
must conserve all of the ID information for later use.


Thanks,

Aaron

__
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Re: [R] Logical in test

2008-12-11 Thread Seeliger . Curt
 OK, this should be trivial but I'm not finding it. I want to compress 
 the test,
 
 if (i==7 | i==10 | i==30 | i==50) {}
 
 into something like
 
 if (i in c(7,10,30,50)) {}
 
 so I can build a excludes vector
 
 excludes - c(7,10,30,50)
 
 and test
 
 if (i in excludes) {}

Works for me.
  excludes - c(7,10,30,50)
  for(i in excludes) { print(i)}
  for(i in 5:30) { if( i %in% excludes) {print(i)} }

What error messages are you getting?
-- 
Curt Seeliger, Data Ranger
Raytheon Information Services - Contractor to ORD
[EMAIL PROTECTED]
541/754-4638
[[alternative HTML version deleted]]

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Re: [R] Principal Component Analysis - Selecting components? + right choice?

2008-12-11 Thread Ravi Varadhan
Hi,

It is generally not the case that the best PC set, say, the top k PCs (where
k  p, p being the number of predcitors) contain the best predictor subset
in linear regression.  Hadi and Ling (Amer Stat, 1998) show that it is even
possible to have an extreme situation where the first (p-1) PCs contribute
nothing towards explaining the variation in the response, yet the last PC
alone contributes everything.   Their theorem is that if the true vector of
regression coefficients is in the direction of the j-th eigenvector (of the
correlation matrix), then the j-th PC alone will contribute everything to
the model fit, while the remaining PCs will contribute zilch.  They
illustrate this phenomenon with a real data set from a classic text on
regression, Draper and Smith.

Ravi.

---

Ravi Varadhan, Ph.D.

Assistant Professor, The Center on Aging and Health

Division of Geriatric Medicine and Gerontology 

Johns Hopkins University

Ph: (410) 502-2619

Fax: (410) 614-9625

Email: [EMAIL PROTECTED]

Webpage:  http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html

 





-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of S Ellison
Sent: Thursday, December 11, 2008 9:37 AM
To: r-help@r-project.org; Corrado
Subject: Re: [R] Principal Component Analysis - Selecting components? +
right choice?

If you're intending to create a model using PCs as predictors, select the
PCs based on whether they contribute significanctly to the model fit.

In chemometrics (multivariate stats in chemistry, among other things), if
we're expecting 3 or 4 PC's to be useful in a principal component
regression, we'd generally start with at least the first half-dozen or so
and let the model fit sort them out.

The reason for not preselecting too rigorously early on is that there's no
guarantee at all that the first couple of PC's are good predictors for what
you're interested in. The're properties of the predictor set, not of the
response set.

Mind you, there used to be something of a gap between chemometrics and
proper statistics; I'm sure chemometricians used to do things with data that
would turn a statistician pale. 

You could also look for a PLS model, which (if I recall correctly) actually
uses the response data to select the latent variables used for prediction.

S

 Corrado [EMAIL PROTECTED] 11/12/2008 11:46:37 
Dear R gurus,

I have some climatic data for a region of the world. They are monthly
averages 1950 -2000 of precipitation (12 months), minimum temperature (12
months), maximum temperature (12 months). I have scaled them to 2 km x 2km
cells, and I have around 75,000 cells.

I need to feed them into a statistical model as co-variates, to use them to
predict a response variable.

The climatic data are obviously correlated: precipitation for January is
correlated to precipitation for February and so on  even precipitation
and temperature are heavily correlated. I did some correlation analysis and
they are all strongly correlated.

I though of running PCA on them, in order to reduce the number of
co-variates I feed into the model.

I run the PCA using prcomp, quite successfully. Now I need to use a criteria
to select the right number of PC. (that is: is it 1,2,3,4?)

What criteria would you suggest?

At the moment, I am using a criteria based on threshold, but that is highly
subjective, even if there are some rules of thumb (Jolliffe,Principal
Component Analysis, II Edition, Springer Verlag,2002). 

Could you suggest something more rigorous?

By the way, do you think I would have been better off by using something
different from PCA?

Best,
--
Corrado Topi

Global Climate Change  Biodiversity Indicators Area 18,Department of
Biology University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: [EMAIL PROTECTED] 

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Re: [R] generate combination multiset (set with repetition)

2008-12-11 Thread baptiste auguie

Hi,

Perhaps you can use expand.grid and then remove the mirror combinations,


values - 1:3
tmp - expand.grid(values, values)
unique.combs - tmp[tmp[, 1]=tmp[, 2], ]
unique.combs[do.call(order, unique.combs), ] # reorder if you wish
  Var1 Var2
111
412
713
522
823
933


I vaguely recall a discussion a few months ago on extending this  
approach to a variable number of arguments to expand.grid.


Hope this helps,

baptiste

On 11 Dec 2008, at 17:00, Reuben Cummings wrote:


Hi,

This has been asked before but not sufficiently answered from what I
could find. How do you create combinations
with repetitions (multisets) in R?

If I have

set - array(1:3)


And I want to choose all combinations of picking 2 numbers, I want to
get a print out like

[,1] [,2]
[1,]11
[2,]12
[3,]13
[4,]22
[5,]23
[6,]33

subsets(set, 2, allow.repeat=T) should work, but I can't get the
multic package to install, t(combn(set,2)) was suggested but it
doesn't produce repetitions; expand.grid(rep(list(1:3), 2)) was also
suggested, but it produces permuations, not combinations.
Additionally, I would like to iterate through each resultant set for
large n (similar to the description for getNextSet {pcalg}). Any
suggestions?

Reuben Cummings

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_

Baptiste Auguié

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

Phone: +44 1392 264187

http://newton.ex.ac.uk/research/emag

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Re: [R] Logical in test

2008-12-11 Thread Stavros Macrakis
i %in% c(7,10,30,50)

On Thu, Dec 11, 2008 at 12:11 PM, David B. Thompson, Ph.D., P.E., D.WRE, CFM
drdbthomp...@gmail.com wrote:

 OK, this should be trivial but I'm not finding it. I want to compress the
 test,

 if (i==7 | i==10 | i==30 | i==50) {}

 into something like

 if (i in c(7,10,30,50)) {}

 so I can build a excludes vector

 excludes - c(7,10,30,50)

 and test

 if (i in excludes) {}

 However, I'm not finding a clue on how to accomplish this, if it can be
 done. Would someone with more R experience lend a helping hand please? A
 reference (so I can continue learning) would also be appreciated.

 Thanks...

 -=d

 David Thompson, Ph.D., P.E., D.WRE, CFM
 Civil Engineer/Hydrologist

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Re: [R] very long integers

2008-12-11 Thread Stavros Macrakis
If they are IDs, you presumably don't need to perform arithmetic on them, so
why not store them as strings?  If you're reading them with read.table, see
the colClasses parameter.  I am not sure how to do this in RODBC;
as.isthere (as in read.table) does not affect columns that look like
numbers --
[perhaps you have to convert on the DBMS side?

   -s

On Thu, Dec 11, 2008 at 11:57 AM, Aaron Robotham smashb...@gmail.comwrote:

 A quick question really:

 I have a database with extremely long integer IDs (eg 588848900971299297),
 which is too big for R to cope with internally (it appears to store as a
 double), and when I do any frequency tables erroneous results appear. Does
 anyone know of a package that extends internal storage up to LONG, or is the
 only solution to read it in as a character from the original data?

 In case anyone is curious, I didn't create the IDs, and in some form I must
 conserve all of the ID information for later use.

 Thanks,

 Aaron

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[R] how to plot implicit functions

2008-12-11 Thread YIHSU CHEN
Dear R users --

I think this question was asked before but there was no reply to it.
I would appreciate any suggestion any of you might have.  I am
interested in plotting several implicit functions (F(x,y,z)=0) on
the same fig. Is there anyone who has an example code of how to do
this?

Thank you

Yihsu

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[R] Complex integration in R

2008-12-11 Thread Borja Soto Varela
Dear R-user

I need a function to approximate a complex integration. My function is:

aprox2=function(s,x,rate){
dexp(x,rate)*exp(-s*x)
}

where argument s is a complex number. I can't use the integrate function
because it's only used with numeric arguments

Does anyone know some function to approximate complex integrals?

Thanks
Borja

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Re: [R] generate combination multiset (set with repetition)

2008-12-11 Thread G. Jay Kerns
Dear Reuben,


On Thu, Dec 11, 2008 at 12:53 PM, baptiste auguie ba...@exeter.ac.uk wrote:
 Hi,

 Perhaps you can use expand.grid and then remove the mirror combinations,

 values - 1:3
 tmp - expand.grid(values, values)
 unique.combs - tmp[tmp[, 1]=tmp[, 2], ]
 unique.combs[do.call(order, unique.combs), ] # reorder if you wish
  Var1 Var2
 111
 412
 713
 522
 823
 933

 I vaguely recall a discussion a few months ago on extending this approach to
 a variable number of arguments to expand.grid.

 Hope this helps,

 baptiste



Here is another way:

library(prob)
urnsamples(1:3, size = 2, ordered = FALSE, replace = TRUE)

You can convert to a matrix with as.matrix(), if desired.

Regards,
Jay


-- 

***
G. Jay Kerns, Ph.D.
Associate Professor
Department of Mathematics  Statistics
Youngstown State University
Youngstown, OH 44555-0002 USA
Office: 1035 Cushwa Hall
Phone: (330) 941-3310 Office (voice mail)
-3302 Department
-3170 FAX
E-mail: gke...@ysu.edu
http://www.cc.ysu.edu/~gjkerns/

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Re: [R] generate combination multiset (set with repetition)

2008-12-11 Thread Charles C. Berry

On Thu, 11 Dec 2008, Reuben Cummings wrote:


Hi,

This has been asked before but not sufficiently answered from what I
could find. How do you create combinations
with repetitions (multisets) in R?

If I have

set - array(1:3)


Why wrap 1:3 in array() ??



And I want to choose all combinations of picking 2 numbers, I want to
get a print out like

[,1] [,2]
[1,]11
[2,]12
[3,]13
[4,]22
[5,]23
[6,]33



For small problems (n  100, say) :

 which( lower.tri( diag( n ), diag=TRUE), arr.ind=TRUE )[,2:1]

For larger problems, something like :

foo - function(n) {
brks - cumsum( n:1 )
k - 1:choose( n+1, 2 )
j - findInterval( k, brks+1 ) + 1
i - k - ( brks-brks[1] )[ j ]
cbind( j, i ) }

If the number in 'set' are not 1:n, you can do a lookup using the results 
from above.



HTH,

Chuck




subsets(set, 2, allow.repeat=T) should work, but I can't get the
multic package to install, t(combn(set,2)) was suggested but it
doesn't produce repetitions; expand.grid(rep(list(1:3), 2)) was also
suggested, but it produces permuations, not combinations.
Additionally, I would like to iterate through each resultant set for
large n (similar to the description for getNextSet {pcalg}). Any
suggestions?

Reuben Cummings

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Charles C. Berry(858) 534-2098
Dept of Family/Preventive Medicine
E mailto:cbe...@tajo.ucsd.edu   UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901

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[R] help: programming loop, binding columns between data sets

2008-12-11 Thread Simon Pickett

Hi,

I often have the problem of combining data sets of different lengths 
together.


Simple example: I have data frame a, with two columns C1 and C2 
and another data frame b with only one column V1.


Data frame b is much bigger than a, but C1 of a has the same 
levels as V1 of b. (so in other words there are multiple instances 
of  a$C1 in b$V1)


I wish to paste a$C2 into a new column in b, where a$C1 == b$V1.

I have always done it this way...

for (i in 1:dim(a)[1])
{b[b$V1 == a$C1[i],c(V2)]=a[i,c(C2)]}

However,
1. It is very slow
2. It is unreliable (in that for no reason at all, I often get NA's in 
the new column of B)
-This usually happens when the code is within a loop, or I have to paste 
multiple columns from a across to b all at once. In this case I 
often have to paste each column one at a time which takes forever.


I often am dealing with very large data sets. I am using R 2.1.1 on 
Windows Vista.


Can anyone suggest a faster/more reliable alternative alternative 
please? Needless to say I am a programming novice.


Thanks in advance,
Simon Pickett.

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Re: [R] repeated searching of no-missing values

2008-12-11 Thread Stavros Macrakis
On Wed, Dec 10, 2008 at 6:39 PM, Bert Gunter gunter.ber...@gene.com wrote:

 ...?tapply says that the first argument is an **atomic** vector. A factor
 is not an atomic vector. So tapply interprets it as such by looking only at
 its representation, which is as integer values.


What is the rationale for this?  If it is just backwards compatibility with
some long-ago implementation decision, perhaps tapply should be deprecated
and replaced by something cleaner (perhaps plyr).  If it is something deeper
than that, it would be useful to know what.

I admit that these details are somewhat obscure and even annoying -- but
 they **are** documented.


No question that it is a good thing that things like this are documented.


 I think that's all we can expect.  Some have lamented the lack of the
 language's perfect consistency in these matters, but I cannot understand how
 that would be possible given its nature, intended, as it is, to be
 **easily** used for high level data manipulation, graphics,statistical
 analysis etc. as well as programming.


As a general rule, consistency makes it *easier* to learn and use a
language.


 There are just too many possible data structures to expect logical
 consistency in their handling throughout...


I am not sure what you mean here. There has been a lot of work in the
programming language community on consistent handling of abstract structures
of various types. Some of their insights may be applicable to future
versions of R.

   -s

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[R] check if a certain ... argument has been passed on to my user-defined function

2008-12-11 Thread Mark Heckmann
Hi,

How can I check if a certain ... argument has been passed on to my
user-defined function or not?

foo - function(data, ...)
{
### here I want to check whether xlab was passed with the ... arguments
### or if the ... arguments did not contain an xlab argument
}

I tried  missing(xlab)  , exists(xlab) and several other things but did not
find a solution.

TIA,
Mark

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Re: [R] check if a certain ... argument has been passed on to my user-defined function

2008-12-11 Thread Henrique Dallazuanna
Try this:

foo - function(data, ...)
{
### here I want to check whether xlab was passed with the ... arguments
### or if the ... arguments did not contain an xlab argument
args - list(...)
return(ifelse(xlab %in% names(args), Exists, Missing))
}

On Thu, Dec 11, 2008 at 4:22 PM, Mark Heckmann mark.heckm...@gmx.de wrote:

 Hi,

 How can I check if a certain ... argument has been passed on to my
 user-defined function or not?

 foo - function(data, ...)
 {
 ### here I want to check whether xlab was passed with the ... arguments
 ### or if the ... arguments did not contain an xlab argument
 }

 I tried  missing(xlab)  , exists(xlab) and several other things but did not
 find a solution.

 TIA,
 Mark

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-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40 S 49° 16' 22 O

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Re: [R] check if a certain ... argument has been passed on to my user-defined function

2008-12-11 Thread Charles C. Berry



See

?match.call

and note the expand.dots arg.

HTH,

Chuck


On Thu, 11 Dec 2008, Mark Heckmann wrote:


Hi,

How can I check if a certain ... argument has been passed on to my
user-defined function or not?

foo - function(data, ...)
{
### here I want to check whether xlab was passed with the ... arguments
### or if the ... arguments did not contain an xlab argument
}

I tried  missing(xlab)  , exists(xlab) and several other things but did not
find a solution.

TIA,
Mark

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Charles C. Berry(858) 534-2098
Dept of Family/Preventive Medicine
E mailto:cbe...@tajo.ucsd.edu   UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901

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Re: [R] getting ISO week

2008-12-11 Thread Hans W. Borchers
Gabor Grothendieck ggrothendieck at gmail.com writes:

 
 format(d, %U) and format(d, %W) give week numbers using
 different conventions.  See ?strptime

Gabor,

the results of format(aDate, W) appear to be incorrect anyway, see:

format(as.Date(2008-01-01), %W) #- 00

There is never a week 0, this should be week 1.

format(Sys.Date(), %W)#- 49

but my business calendar says today's (Dec. 11, 2008) week is week 50
which is what Brian Ripleys proposed 'strftime(x, %V)' returns.

There could be a format %E (not used up to now) for returning a
correct week number according to the European standard.

Yours,  Hans Werner

 On Thu, Dec 11, 2008 at 7:43 AM, Gustaf Rydevik
 gustaf.rydevik at gmail.com wrote:
  Hi all,
 
  Is there a simple function already implemented for getting the ISO
  weeks of a Date object?
  I couldn't find one, and so wrote my own function to do it, but would
  appreciate a pointer to the default way. If a function is not yet
  implemented, could the code below be of interest to submit to CRAN?
 
  Best Regards,
 
  Gustaf
 
  
 
 ... [rest deleted]
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Re: [R] getting ISO week

2008-12-11 Thread Gabor Grothendieck
According to the definition in ?strptime (which is not the same as the
ISO definition):

format(x, %W) returns

Week of the year as decimal number (00–53) using Monday as the first
day of week (and typically with the first Monday of the year as day 1
of week 1). The UK convention.

The first day of 2008 is a Tuesday which means that 2008 starts in week 0.

On Thu, Dec 11, 2008 at 2:31 PM, Hans W. Borchers hwborch...@gmail.com wrote:
 Gabor Grothendieck ggrothendieck at gmail.com writes:


 format(d, %U) and format(d, %W) give week numbers using
 different conventions.  See ?strptime

 Gabor,

 the results of format(aDate, W) appear to be incorrect anyway, see:

format(as.Date(2008-01-01), %W) #- 00

 There is never a week 0, this should be week 1.

format(Sys.Date(), %W)#- 49

 but my business calendar says today's (Dec. 11, 2008) week is week 50
 which is what Brian Ripleys proposed 'strftime(x, %V)' returns.

 There could be a format %E (not used up to now) for returning a
 correct week number according to the European standard.

 Yours,  Hans Werner

 On Thu, Dec 11, 2008 at 7:43 AM, Gustaf Rydevik
 gustaf.rydevik at gmail.com wrote:
  Hi all,
 
  Is there a simple function already implemented for getting the ISO
  weeks of a Date object?
  I couldn't find one, and so wrote my own function to do it, but would
  appreciate a pointer to the default way. If a function is not yet
  implemented, could the code below be of interest to submit to CRAN?
 
  Best Regards,
 
  Gustaf
 
  

 ... [rest deleted]
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[R] R imperfections? -- was: repeated searching of no-missing values

2008-12-11 Thread Bert Gunter
Replies inline below.

Best regards,
-- Bert
___


From: macra...@gmail.com [mailto:macra...@gmail.com] On Behalf Of Stavros
Macrakis
Sent: Thursday, December 11, 2008 10:53 AM
To: Bert Gunter
Cc: Patrizio Frederic; r-help@r-project.org
Subject: Re: [R] repeated searching of no-missing values


On Wed, Dec 10, 2008 at 6:39 PM, Bert Gunter gunter.ber...@gene.com wrote:


...?tapply says that the first argument is an **atomic** vector. A
factor is not an atomic vector. So tapply interprets it as such by looking
only at its representation, which is as integer values.



What is the rationale for this?  If it is just backwards compatibility with
some long-ago implementation decision, perhaps tapply should be deprecated
and replaced by something cleaner (perhaps plyr).  If it is something deeper
than that, it would be useful to know what.


Rationale? -- you'll have to ask the developers. As for deprecating (or
changing) tapply: do you have any idea how much code that could break?! I
think that is probably a wholly unrealistic suggestion.

The way forward is through efforts like Hadley's plyr package.  Among other
things, that's what packages are for. Indeed, as you probably know, packages
like R.oo and proto allow one to use a whole different programming
language/paradigm within R, while still taking advantage of all of R's
existing built-in functionality. Except for possible performance penalties,
I don't see how you can ask for much more than that.

So, no, R is certainly not perfect. I'm sure that if they could go back 20
years with today's knowledge and experience, the developers would do some
things differently. That's life -- and progress! But I think any objective
assessment -- and certainly those of us who use it day in and day out in our
work -- would consider R a truly amazing software product, warts or no. 

Hence, may I suggest that instead of merely pointing out its (often well
known,btw) imperfections and inelegancies,  you instead move to the
developers' forum and contribute improvements. This is, I believe, a
standard way for people with programming expertise like yourself to
contribute to open source development. Although the developers may be a bit
crotchety at times (I think often appropriately so given the extraordinary
effort they've put in), I think you would find that they would welcome
sincere efforts to help them improve R.

***



I admit that these details are somewhat obscure and even annoying --
but they **are** documented.



No question that it is a good thing that things like this are documented.
 


I think that's all we can expect.  Some have lamented the lack of
the language's perfect consistency in these matters, but I cannot understand
how that would be possible given its nature, intended, as it is, to be
**easily** used for high level data manipulation, graphics,statistical
analysis etc. as well as programming.


As a general rule, consistency makes it *easier* to learn and use a
language.
***
Of course!
***
 

There are just too many possible data structures to expect logical
consistency in their handling throughout...


I am not sure what you mean here. There has been a lot of work in the
programming language community on consistent handling of abstract structures
of various types. Some of their insights may be applicable to future
versions of R.

***
No doubt. That's progress. Are you going to write this future version? I
certainly am not -- and CAN not (being a bear of but little brain)!
***

   -s

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[R] Row order in plot

2008-12-11 Thread qroberts

I'm new to R so forgive me if this seems like a simple question:

So I have table where the row titles are string variables. When I plot the
data with rows along the x-axis, the data is ordered alphabetically as
opposed to the order of the table.

How can I preserve the row order of the table in the plot?

Thanks in advance.
-- 
View this message in context: 
http://www.nabble.com/Row-order-in-plot-tp20962774p20962774.html
Sent from the R help mailing list archive at Nabble.com.

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Re: [R] Row order in plot

2008-12-11 Thread Sarah Goslee
It would be easier to answer your question if we knew what your
data look like, what R commands you've tried, and what result
you want.

One possibility: plot the data against 1:nrow(yourdata), and add
the row names as labels.

Sarah

On Thu, Dec 11, 2008 at 2:35 PM, qroberts lvaic...@bu.edu wrote:

 I'm new to R so forgive me if this seems like a simple question:

 So I have table where the row titles are string variables. When I plot the
 data with rows along the x-axis, the data is ordered alphabetically as
 opposed to the order of the table.

 How can I preserve the row order of the table in the plot?

 Thanks in advance.



-- 
Sarah Goslee
http://www.functionaldiversity.org

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[R] is there a way to recursilvely lapply

2008-12-11 Thread Whit Armstrong
for a simple example:

x - list()
x[[a]] - list(a=c(1,2,3),b=c(3,4,5))
x[[b]] - list(a=c(6,7,8),b=c(9,10,11))

lapply(x,sum)


this fails w/
Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument

Just wondering if I have overlooked something obvious.

one can also do:

lapply(x,lapply,sum)

but that assumes that you already know how many levels you have, and
that all the levels are consistent.

-Whit

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Re: [R] getting ISO week

2008-12-11 Thread Hans W. Borchers
Gabor Grothendieck ggrothendieck at gmail.com writes:

 
 According to the definition in ?strptime (which is not the same as the
 ISO definition):
 
 format(x, %W) returns
 
 Week of the year as decimal number (00–53) using Monday as the first
 day of week (and typically with the first Monday of the year as day 1
 of week 1). The UK convention.
 
 The first day of 2008 is a Tuesday which means that 2008 starts in week 0.

Yes I read that but it is still misleading and -- I think -- incorrect. 
See www.dateandtime.org/calendar to find out that this is week 50 even 
in the UK.
We would have had a lot of misplaced business meetings in our company if 
the week numbers in Great Britain, Germany, and Sweden would actually be 
different.

Hans Werner

 
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Re: [R] is there a way to recursilvely lapply

2008-12-11 Thread Gabor Grothendieck
This will recursively lapply and may or may not be
what you are looking for:

rapply(x, sum)

On Thu, Dec 11, 2008 at 2:59 PM, Whit Armstrong
armstrong.w...@gmail.com wrote:
 for a simple example:

 x - list()
 x[[a]] - list(a=c(1,2,3),b=c(3,4,5))
 x[[b]] - list(a=c(6,7,8),b=c(9,10,11))

 lapply(x,sum)


 this fails w/
 Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument

 Just wondering if I have overlooked something obvious.

 one can also do:

 lapply(x,lapply,sum)

 but that assumes that you already know how many levels you have, and
 that all the levels are consistent.

 -Whit

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Re: [R] getting ISO week

2008-12-11 Thread Gabor Grothendieck
Perhaps you mean is that the definition ought be otherwise but
at least according to one standard the definition is correct:

http://www.opengroup.org/onlinepubs/009695399/functions/strptime.html

On Thu, Dec 11, 2008 at 3:01 PM, Hans W. Borchers hwborch...@gmail.com wrote:
 Gabor Grothendieck ggrothendieck at gmail.com writes:


 According to the definition in ?strptime (which is not the same as the
 ISO definition):

 format(x, %W) returns

 Week of the year as decimal number (00–53) using Monday as the first
 day of week (and typically with the first Monday of the year as day 1
 of week 1). The UK convention.

 The first day of 2008 is a Tuesday which means that 2008 starts in week 0.

 Yes I read that but it is still misleading and -- I think -- incorrect.
 See www.dateandtime.org/calendar to find out that this is week 50 even
 in the UK.
 We would have had a lot of misplaced business meetings in our company if
 the week numbers in Great Britain, Germany, and Sweden would actually be
 different.

 Hans Werner

 
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[R] candisc plotting

2008-12-11 Thread Pete Shepard
Hello,

I have a file with two dependent variables (three and five) and one
independent variable. I do  i.mod - lm(cbind(three, five) ~ species,
data=i.txt) and get the following output:


Coefficients:
 three   five
(Intercept)   9.949   9.586
species  -1.166  -1.156

I do a i.can-candisc(i.mod,data=i):

and get the following output:

Canonical Discriminant Analysis for species:

CanRsq Eigenvalue Difference Percent Cumulative
1 0.0965060.10681100100

Test of H0: The canonical correlations in the
current row and all that follow are zero
LR test stat approx F num Df den Df   Pr( F)
10.903   63.875  1598 6.859e-15 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

this is different than the output I get with SAS:

 Eigenvalue Difference Proportion Cumulative  Ratio F Value
Num DF Den DF Pr  F

   1 0.10681. 1. 0.90349416
31.88  2597 .0001


I am also wondering how to plot the can1*can1 like it is done in SAS.

proc plot;
plot can1*can1=species;
format species spechar.;
title2 'Plot of Constits_vs_cassettes';
 run;

Thanks

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Re: [R] call lattice function in a function passing groups argument

2008-12-11 Thread Deepayan Sarkar
On Thu, Dec 11, 2008 at 2:55 AM, Thomas Zumbrunn t.zumbr...@unibas.ch wrote:
 I'm trying to use a lattice function within a function and have problems
 passing the groups argument properly. Let's say I have a data frame

 d - data.frame(x = rnorm(100), y = c(a, b))

 and want to plot variable x in a densityplot, grouped by the variable y, then
 I would do something like

 densityplot(~ x, d, groups = y)

 If however I wanted to call the function densityplot within a function and
 pass the groups argument as an argument of that function, how would I have
 to proceed? It is not as straightforward as

 f - function(data, groupvar) {
  densityplot(~ x, data, groups = groupvar)
 }

 probably because the lattice function densityplot.formula preprocesses
 the groups argument with

Yes, that's the price of non-standard evaluation.

 groups - eval(substitute(groups), data, environment(formula))

 It there a way how I could pass the groups argument in the function f?

The obvious solution is to evaluate 'groupvar' yourself:

f - function(data, groupvar) {
  groupvar - eval(substitute(groupvar), data, parent.frame())
  densityplot(~ x, data, groups = groupvar)
}

A more general solution (where 'groupvar' may be missing) is to use
match.call() etc. (e.g., see lattice:::dotplot.formula)

-Deepayan

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Re: [R] is there a way to recursilvely lapply

2008-12-11 Thread Prof Brian Ripley

On Thu, 11 Dec 2008, Whit Armstrong wrote:


for a simple example:

x - list()
x[[a]] - list(a=c(1,2,3),b=c(3,4,5))
x[[b]] - list(a=c(6,7,8),b=c(9,10,11))

lapply(x,sum)


this fails w/
Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument

Just wondering if I have overlooked something obvious.


rapply?  Which is linked from ?lapply (I just checked).  Perhaps


rapply(x, sum)

a.a a.b b.a b.b
  6  12  21  30

or


rapply(x, sum, how=list)

$a
$a$a
[1] 6
.



one can also do:

lapply(x,lapply,sum)

but that assumes that you already know how many levels you have, and
that all the levels are consistent.

-Whit

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Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
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Re: [R] R imperfections? -- was: repeated searching of no-missing values

2008-12-11 Thread Stavros Macrakis
Bert,

Thanks for your reply.  I suspect we agree more than you might think

Comments inline below.  I've snipped out parts.

-s

On Thu, Dec 11, 2008 at 2:45 PM, Bert Gunter gunter.ber...@gene.com wrote:

 Rationale? -- you'll have to ask the developers


Hmm.  It would be nice if this could be documented for new users -- and for
posterity. But I admit that other projects I have worked on don't do a
particularly good job of documenting such things, either.


 As for deprecating (or changing) tapply: do you have any idea how much code
 that could break?! I think that is probably a wholly unrealistic
 suggestion


Ah, perhaps my terminology isn't clear.  In the programming world,
deprecating (as opposed to removing or changing) a feature means declaring
it obsolete and not-to-be-recommended (or as you put it somewhat obscure
and even annoying) while continuing to support it for backwards
compatibility.  So tapply would continue to exist and to work both for
legacy code and for users who prefer it, but it would not be taught to new
users, and its documentation would cross-reference the currently recommended
approach.

The way forward is through efforts like Hadley's plyr package


Agreed, and ideally the user and developer community would eventually
converge on one or another such package and integrate it into the core
system, to avoid balkanization of the user community.


 ...packages like R.oo and proto allow one to use a whole different
 programming language/paradigm within R, while still taking advantage of all
 of R's existing built-in functionality. Except for possible performance
 penalties, I don't see how you can ask for much more than that


I certainly agree that exploring other approaches in add-on packages is a
good thing.  Even better to progressively deprecate features which are
obscure and even annoying at the same time.


 ...So, no, R is certainly not perfect. I'm sure that if they could go back
 20
 years with today's knowledge and experience, the developers would do some
 things differently


We cannot change the past, but we can make a better future without hurting
current users!

...any objective assessment -- and certainly those of us who use it day in
 and day out in our
 work -- would consider R a truly amazing software product, warts or no


I agree entirely -- I have come to use R after considering a variety of
alternatives for my work, and am delighted with its functionality and strong
user community. I admit, though, that the learning curve has been
surprisingly steep, largely because of design inconsistencies and
idiosyncratic terminology.


 Hence, may I suggest that instead of merely pointing out its (often well
 known,btw) imperfections and inelegancies,  you instead move to the
 developers' forum and contribute improvements. This is, I believe, a
 standard way for people with programming expertise like yourself to
 contribute to open source development


Agreed, and I have contributed to Maxima over the years.  I am quite new to
R, though, and just getting my bearings.  I haven't even looked at the
underlying implementation yet. I do intend to contribute in the future.

  -s

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Re: [R] 2-Y-axes on same plot

2008-12-11 Thread Robert W. Baer, Ph.D.

Joe Trubisz wrote:

Hi...

Is this possible in R?

I have 2-sets of data, that were collected simultaneously using 
2-different data acquisition schemes.

The x-values are the same for both.
The y-values have different ranges (16.4-37.5 using one method, 557-634 
using another).


In theory, if you plot both plots on top of each other, the graphs should 
overlap. The problem I'm having is trying to have to different sets of 
y-values appear in the same graph, but scaled in the same vertical space. 
I've seen this done in publications, but not sure if it can be done in R.


Here's a brute force graph with two sets of y-axis
# set up some fake test data
time - seq(0,72,12)
betagal.abs - c(0.05,0.18,0.25,0.31,0.32,0.34,0.35)
cell.density - c(0,1000,2000,3000,4000,5000,6000)

#add extra space to right margin of plot within frame
par(mar=c(5, 4, 4, 4) + 0.1)

# Plot first set of data and draw its axis
plot(time, betagal.abs, pch=16, axes=F, ylim=c(0,1), xlab=, ylab=, 
type=b,col=black, main=Mike's test data)

axis(2, ylim=c(0,1),col=black)
mtext(Beta Gal Absorbance,side=2,line=2.5)
box()

# Allow a second plot on the same graph
par(new=T)

# Plot the second plot and put axis scale on right
plot(time, cell.density, pch=15,  xlab=, ylab=, ylim=c(0,7000), axes=F, 
type=b, col=red)

mtext(Cell Density,side=4,col=red,line=2.5)
axis(4, ylim=c(0,7000), col=red,col.axis=red)

# Draw the time axis
axis(1,pretty(range(time),10))
mtext(Time (Hours),side=1,col=black,line=2.5)

# Add Legend
legend(5,7000,legend=c(Beta Gal,Cell 
Density),text.col=c(black,red),pch=c(16,15),col=c(black,red))


HTH,

Rob Baer

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[R] Resampling physiological data using R?

2008-12-11 Thread tsunhin wong
Dear all R users,

I am going to use R to process some of my physiological data about eye.

The problem is the recording machine does not sample in a reliably
constant rate: the time intervals between data sampled can vary from
9msec to ~120msec, while most around in the 15-30msec range.
The below is a fraction of a single data file of a trial:

TimeCursorX CursorY Pupilsize
1811543 -1  -1  -1
1811563 -1  -1  -1
1811584 511 370 4.175665
1811603 511 368 4.181973
1811624 521 368 4.210732
1811644 512 377 4.149632
1811664 524 377 4.275845
1811684 518 368 4.236212
1811703 516 370 4.238384
1811725 507 364 4.181157
1811744 509 371 4.185016
1811764 509 377 4.231987
1811784 514 387 4.252449
1811802 515 388 4.273726

My goal is to resample these data so that the Time column
increments by a regular interval, and the other columns of data are
the averages (or estimates) at the point in time according to
available data points.
I have done something that I use a regular interval that is larger
than the naturally occurring record machine, i.e.  120msec for
example, and acquire an average of the available data points for any
particular regular time interval.

Now, I need to achieve resampling for smaller regular interval: i.e.
5msec intervals, and interpolate / intrapolate the missing data points
from the available ones.
i.e. I may have to split up data points into the number of the regular
intervals that it may occupied in time.

Do you know if there is any package that is doing something similar?
And because of the size of the data and computational demand (1500
files each with 2000-8000+ lines), can you suggest me some
(algorithmically) more efficient way of doing this?

Thanks a lot!

Regards,

  John

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Re: [R] is there a way to recursilvely lapply

2008-12-11 Thread Whit Armstrong
Thanks, Gabor and Prof. Ripley.

Sorry for the oversight.

I grepped the lapply help for recursive prior to sending my question.

why does it appear as *r*ecursive in the help file? or is that just
a formating problem on my machine?

-Whit


On Thu, Dec 11, 2008 at 3:13 PM, Prof Brian Ripley
rip...@stats.ox.ac.uk wrote:
 On Thu, 11 Dec 2008, Whit Armstrong wrote:

 for a simple example:

 x - list()
 x[[a]] - list(a=c(1,2,3),b=c(3,4,5))
 x[[b]] - list(a=c(6,7,8),b=c(9,10,11))

 lapply(x,sum)


 this fails w/
 Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument

 Just wondering if I have overlooked something obvious.

 rapply?  Which is linked from ?lapply (I just checked).  Perhaps

 rapply(x, sum)

 a.a a.b b.a b.b
  6  12  21  30

 or

 rapply(x, sum, how=list)

 $a
 $a$a
 [1] 6
 .


 one can also do:

 lapply(x,lapply,sum)

 but that assumes that you already know how many levels you have, and
 that all the levels are consistent.

 -Whit

 __
 R-help@r-project.org mailing list
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 PLEASE do read the posting guide
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 --
 Brian D. Ripley,  rip...@stats.ox.ac.uk
 Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
 University of Oxford, Tel:  +44 1865 272861 (self)
 1 South Parks Road, +44 1865 272866 (PA)
 Oxford OX1 3TG, UKFax:  +44 1865 272595


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[R] Equivalent to Full Information Maximum Likelihood (FIML) in R?

2008-12-11 Thread Pilgrim Regression
Is there an equivalent to MPlus's Full Information Maximum Likelihood (FIML)
missing data estimator for R? If so, is there a way to take covariance
structures produced by such a package and perform multiple regression with
these?

If you are unfamiliar with Mplus' FIML below is a link to their manual.
Their estimation technology is discussed on page 25. I have asked the
developer of the mvnmle and he was unsure if this package similar.

http://www.statmodel.com/download/techappen.pdf

Thanks,

Sam
-- 
http://theregressingpilgrim.blogspot.com/

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Re: [R] R imperfections? -- was: repeated searching of no-missing values

2008-12-11 Thread Wacek Kusnierczyk
replies inline below.


Bert Gunter wrote:
 Replies inline below.


 [bert (?)]...?tapply says that the first argument is an **atomic** 
 vector. A
 factor is not an atomic vector. So tapply interprets it as such by looking
 only at its representation, which is as integer values.
   


 [stavros] What is the rationale for this?  If it is just backwards 
 compatibility with
 some long-ago implementation decision, perhaps tapply should be deprecated
 and replaced by something cleaner (perhaps plyr).  If it is something deeper
 than that, it would be useful to know what.

 
 [bert] Rationale? -- you'll have to ask the developers. As for deprecating (or
 changing) tapply: do you have any idea how much code that could break?! I
 think that is probably a wholly unrealistic suggestion.
   

do you have any idea how much old code has been broken in the history of
programming just because programming languages moved from version x to
version x+1?  the argument that old code would be broken is repeated
here ad nauseam, literally.  there always is a tradeoff between
protecting the old developers against the need for reimplementation of
existing code and protecting the future developers against the need to
spend days on figuring our how to hack around broken designs and
implementations.

 The way forward is through efforts like Hadley's plyr package.  Among other
 things, that's what packages are for. 

packages play an important role in about every language.  but packages,
especially ones written by third parties, should serve as an *extension*
of the core functionality, and not as a replacement.  perhaps it is just
fine to say that a function from plyr should be used instead of tapply
(which, note, is in the base package).  but perhaps the core stuff
should rather evolve than be duplicated by external patches.

as to the original problem, since you (bert) say:

?tapply says that the first argument is an **atomic** vector. A factor
is not an atomic vector. So tapply interprets it as such by looking only
at its representation, which is as integer values.

can you explain the following:

is.atomic(as.factor(1:10))
# TRUE

is.atomic(factor(0))
# TRUE

?is.atomic says:

'is.atomic' returns 'TRUE' if 'x' is an atomic vector (or 'NULL') and
'FALSE' otherwise.

which seems incoherent with the above, and also with the following:

f = factor(0)
is.atomic(f)
# TRUE
is.vector(f)
# FALSE

?vector says:

Note that factors are _not_ vectors;  'is.vector' returns 'FALSE'

if f is not a vector, how can it be an atomic vector?  perhaps
'is.atomic' does not mean what i would naively assume reading the docs; 
with r, one has to learn not to use common sense, as in, e.g., the case
of sort.list.


 Indeed, as you probably know, packages
 like R.oo and proto allow one to use a whole different programming
 language/paradigm within R, while still taking advantage of all of R's
 existing built-in functionality. Except for possible performance penalties,
 I don't see how you can ask for much more than that.
   

given how comments such as those of stavros or mine are typically
answered, indeed one cannot expect much more.  the question is, why
would one not want to ask for more?

 So, no, R is certainly not perfect. I'm sure that if they could go back 20
 years with today's knowledge and experience, the developers would do some
 things differently. That's life -- and progress! But I think any objective
 assessment -- and certainly those of us who use it day in and day out in our
 work -- would consider R a truly amazing software product, warts or no. 

 Hence, may I suggest that instead of merely pointing out its (often well
 known,btw) imperfections and inelegancies,  you instead move to the
 developers' forum and contribute improvements. This is, I believe, a
 standard way for people with programming expertise like yourself to
 contribute to open source development. Although the developers may be a bit
 crotchety at times (I think often appropriately so given the extraordinary
 effort they've put in), I think you would find that they would welcome
 sincere efforts to help them improve R.
   

again, same send-a-patch talk.  can't you possibly dissect between
design and implementation?  should every conceptual discussion be
replaced by a flow of patches?  python's peps have already been
mentioned;  another counterexample is jcp.  i agree that contributing
code is desirable, but discarding any other initiative  right away is
plainly rude, even if not verbally.




   I think that's all we can expect.  Some have lamented the lack of
 the language's perfect consistency in these matters, but I cannot understand
 how that would be possible given its nature, intended, as it is, to be
 **easily** used for high level data manipulation, graphics,statistical
 analysis etc. as well as programming.


 As a general rule, consistency makes it *easier* to learn and use a
 language.
 ***
 Of course!
 ***
   

radio erewan strikes again?  

Re: [R] is there a way to recursilvely lapply

2008-12-11 Thread Prof Brian Ripley

On Thu, 11 Dec 2008, Whit Armstrong wrote:


Thanks, Gabor and Prof. Ripley.

Sorry for the oversight.

I grepped the lapply help for recursive prior to sending my question.

why does it appear as *r*ecursive in the help file? or is that just
a formating problem on my machine?


It is marked as bold: I presume you are reading text help?



-Whit


On Thu, Dec 11, 2008 at 3:13 PM, Prof Brian Ripley
rip...@stats.ox.ac.uk wrote:

On Thu, 11 Dec 2008, Whit Armstrong wrote:


for a simple example:

x - list()
x[[a]] - list(a=c(1,2,3),b=c(3,4,5))
x[[b]] - list(a=c(6,7,8),b=c(9,10,11))

lapply(x,sum)


this fails w/
Error in FUN(X[[1L]], ...) : invalid 'type' (list) of argument

Just wondering if I have overlooked something obvious.


rapply?  Which is linked from ?lapply (I just checked).  Perhaps


rapply(x, sum)


a.a a.b b.a b.b
 6  12  21  30

or


rapply(x, sum, how=list)


$a
$a$a
[1] 6
.



one can also do:

lapply(x,lapply,sum)

but that assumes that you already know how many levels you have, and
that all the levels are consistent.

-Whit

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--
Brian D. Ripley,  rip...@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax:  +44 1865 272595





--
Brian D. Ripley,  rip...@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax:  +44 1865 272595

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[R] Extract rows from data frame based on row names from another data frame

2008-12-11 Thread Wade Wall
Hi all,

Is there a function to extract row names from a data frame based on
row names from another data frame?  I can write a loop function to do
this, but this may be inefficient in terms of processing.

thanks for any information,

Wade

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[R] simulate spatial data

2008-12-11 Thread Daniel Malter
Hi, I am simulating 2-dimensional data using the RandomFields library and
the gaussRF function therein. While this is done with the code below, I
would like the landscape to be continuous or smooth at the edges. That is, I
would like the upper edge to smoothly connect to the lower edge AND the
right edge to smoothly connect to the left edge. I cannot figure out how to
do this. I would greatly appreciate pointers to the right function, a
different package, or any other viable approach.

Best,
Daniel


library(RandomFields)
PrintModelList() ## the complete list of implemented models

model - stable
mean - 0
variance - 10
nugget - 0 #noise around the structure
scale - 10  #structure/patchiness
alpha - 2 ## see help(CovarianceFct) for additional
## parameters of the covariance functions
step - 1 ## nicer, but also time consuming if step - 0.1
x - seq(0, 100, step)
y - seq(0, 100, step)

f - GaussRF(x=x, y=y, model=model,grid=T, param=c(mean, variance, nugget,
scale, alpha))   #

par(mfcol=c(1,2))
image(x, y, f)
contour(f) 

-
cuncta stricte discussurus

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