Re: [R] lattice panel.lmline problem

2007-09-10 Thread Ross Darnell
Thanks Frede

I didn't know about the r type. 

Ross Darnell


-Original Message-
From: Frede Aakmann Tøgersen [mailto:[EMAIL PROTECTED]
Sent: Mon 10-Sep-07 4:45 PM
To: Ross Darnell; r-help@stat.math.ethz.ch
Subject: SV: [R] lattice panel.lmline problem
 
Why not use the more simple

xyplot(total.fat~x|variable,groups=Group,
   data=tmp1,type=c(p,r))

???

See ?panel.xyplot and especially the type argument of that panel function.




Best regards

Frede Aakmann Tøgersen
Scientist


UNIVERSITY OF AARHUS
Faculty of Agricultural Sciences
Dept. of Genetics and Biotechnology
Blichers Allé 20, P.O. BOX 50
DK-8830 Tjele

Phone:   +45 8999 1900
Direct:  +45 8999 1878

E-mail:  [EMAIL PROTECTED]
Web:   http://www.agrsci.org

This email may contain information that is confidential.
Any use or publication of this email without written permission from Faculty of 
Agricultural Sciences is not allowed.
If you are not the intended recipient, please notify Faculty of Agricultural 
Sciences immediately and delete this email.


 

 -Oprindelig meddelelse-
 Fra: [EMAIL PROTECTED] 
 [mailto:[EMAIL PROTECTED] På vegne af Ross Darnell
 Sendt: 10. september 2007 07:55
 Til: r-help@stat.math.ethz.ch
 Emne: [R] lattice panel.lmline problem
 
 I am wanting to generate panels showing scatterplots with the 
 linear fitted line for two groups within each panel superimposed.
 
 I have two conditioning factors, variable and Group and I 
 want separate panels for each level of variable
 
 with different symbols and lmlines for each level of 
 Group. However all observations for a group are missing for 
 some variables so I would still like the points and lmline 
 for the observed group plotted for that variable(panel).
 
  
 
 My attempt is 
 
  
 
 print(xyplot(total.fat~x|variable,data=tmp1,subscripts=TRUE,
 
  
 scales=list(x=list(relation=free)),xlab=,groups=Group,
 
  panel=function(x,y,subscripts,...){
 
panel.superpose(x,y,subscripts,...)
 
if(length(x[subscripts])!=0)
 
  
 {panel.superpose(x,y,panel.groups=panel.lmline,subscripts,...)}}))
 
  
 
 Which gives an error
 
  
 
 Error in lm.fit(x, y, offset = offset, singular.ok = 
 singular.ok, ...) :
 
 
 0 (non-NA) cases
 
  
 
  
 
 Which occurs when the first panel with all values for one 
 group are missing.
 
 The same error is returned if I replace the last line without the if
 statement which obviously means it's ignored.
 
  
 
 Of course I may be taking the wrong tack completely to get 
 the result I need. Any advice would be appreciated
 
   
 
  
 
 Ross Darnell
 
 
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Re: [R] install packages automatically

2007-09-10 Thread Ross Darnell
Try

?update.packages

Ross Darnell

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Wensui Liu
Sent: Tuesday, 11 September 2007 11:45 AM
To: r-help@stat.math.ethz.ch
Subject: [R] install packages automatically

Dear Listers,
I am a little tired of installing all packages I want every time when
I instill a new version of R.
Say, if I have a list of packages I need to use, is it possible to
tell R to install them all for me automatically rather than I install
them one by one?
Thx.

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[R] lattice panel.lmline problem

2007-09-09 Thread Ross Darnell
I am wanting to generate panels showing scatterplots with the linear
fitted line for two groups within each panel superimposed.

I have two conditioning factors, variable and Group and I want
separate panels for each level of variable

with different symbols and lmlines for each level of Group. However
all observations for a group are missing for some variables so I would
still like the points and lmline for the observed group plotted for that
variable(panel).

 

My attempt is 

 

print(xyplot(total.fat~x|variable,data=tmp1,subscripts=TRUE,

 scales=list(x=list(relation=free)),xlab=,groups=Group,

 panel=function(x,y,subscripts,...){

   panel.superpose(x,y,subscripts,...)

   if(length(x[subscripts])!=0)

 
{panel.superpose(x,y,panel.groups=panel.lmline,subscripts,...)}}))

 

Which gives an error

 

Error in lm.fit(x, y, offset = offset, singular.ok = singular.ok, ...) :


0 (non-NA) cases

 

 

Which occurs when the first panel with all values for one group are
missing.

The same error is returned if I replace the last line without the if
statement which obviously means it's ignored.

 

Of course I may be taking the wrong tack completely to get the result I
need. Any advice would be appreciated

  

 

Ross Darnell


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Re: [R] Question on graphs and simple if statements

2007-09-02 Thread Ross Darnell
The answer to your first question is

curve(ifelse((x-1)(x1),x^2+1,x+2),from=-10,to=10)

Sorry I cannot understand the next part of your query.

Ross Darnell

On Sun, 2007-09-02 at 00:31 -0700, JHawk3 wrote:
 Hi all,
 
 I'm a relatively new user to the R interface, and am trying to do some basic
 operations. So far I've used the curve() command to plot graphs. This has a
 couple of limitations, namely trying to do piecewise graphs. Basically, I'm
 looking for how to do if and while loops for making a graph.
 
 in simple code, something like:
 
 if x is on the interval [-1,1], x=x^2+1
 otherwise, x=x^2
 
 something along those lines. I also am wondering if it's possible to graph
 something like this:
 while(n20)
 {
 curve(1/n^2, -1,1)
 n++
 }
 Along these same lines, is there a way to graph finite series?
 
 Thank you for your time and your replies.


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Re: [R] customizing the color and point shape for each line drawn using lattice's xyplot

2007-08-30 Thread Ross Darnell
Does this help

common.without.Method4 - subset(common, Method!=4)
xyplot(MeanBxg ~ PercentVarExplained | bdg.f * bdx.f,
data=common.without.Method4,
groups=Method.f, type=l,  auto.key=T)

Ross Darnell

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Gen
Sent: Thursday, 30 August 2007 2:51 PM
To: r-help@stat.math.ethz.ch
Subject: [R] customizing the color and point shape for each line drawn
using lattice's xyplot


Description of what I am trying to do:
I am using the xyplot code below to plot the variable MeanBxg against
the
variable PercentVarExplained for all 9 possible combinations of
variables
bdg and bdx.  Within each of these 9 scenarios I am plotting a
separate
line for each of up to 9 different methods that I used to estimate the
variable MeanBxg. These methods are identified by the numeric variable
called Method.  Giving me one plot with 9 figures and each of the
figures
contains 9 lines. 

My problem arises because I would like to repeat the creation of this
plot 8
times, in each instance only a subset (eg 6) of the 9 methods are used
(a
different subset each time). 

What I can't figure out:
I would like to learn how to specify the exact line color that
corresponds
to each method such that Method==1 will always be represented by the
same
color (in every plot that it appears in).  Where two methods that I used
were of the same family of methods (say method==1 and method==2 made the
same assumptions about the data)  I would like to, if possible,
represent
the two methods using the same color and distinguish them by the symbol
used
to represent points on the line. 

My code as it currently stands:
xyplot(MeanBxg ~ PercentVarExplained | bdg.f * bdx.f, data=common,
groups=common$Method.f, type=l, subset= Method!=4, auto.key=T)

As the code is, the default colors assigned are repeated causing
different
methods to be represented by the same color with no way to distinguish
them
(I have not succeeded in plotting lines and points simultaneously).  

Side question: When I subset the data to particular methods, is there a
way
to remove the excluded methods from the key as well? (in my code
Method is
a numeric variable, and Method.f corresponds to the lengthy
descriptions
of each method for the purpose of the key)

Thank you very much for your help. 
Genevieve



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e-drawn-using-lattice%27s-xyplot-tf4351934.html#a12400517
Sent from the R help mailing list archive at Nabble.com.

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Re: [R] customizing the color and point shape for each line drawn using lattice's xyplot

2007-08-30 Thread Ross Darnell
Then you can regenerate the factor by

common.without.Method4 - subset(common, Method!=4)

common.without.Method4 - transform(common.without.Method4,
Method = factor(Method))

Ross Darnell

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Gen
Sent: Friday, 31 August 2007 1:42 AM
To: r-help@stat.math.ethz.ch
Subject: Re: [R] customizing the color and point shape for each line
drawn using lattice's xyplot


Thank you for your suggestion. Unfortunately it does not appear to
matter if
the data is subsetted before the xyplot command or within it.  The
problem
remains. 

I was able to remove method 4 entirely from the key by using your
suggestion
to subset the dataset common, and then creating a new variable to
assign
labels for just this subset common.without.Method4$method.not4.f  The
resulting code was:

xyplot(MeanBxg ~ PercentVarExplained | bdg.f * bdx.f,
data=common.without.Method4, groups=method.not4.f, type=l,
auto.key=T)

This however leads to lack of continuity between plots, as when I
exclude
methods 4 and 6 in my second plot, using the same approach, the color
that
had corresponds to methods 7, 8 and 9 in plot one is automatically
changed
in plot two.  The subsetting may work, so long as I can dictate line
color
and symbol type in each plot. 



Ross Darnell wrote:
 
 Does this help
 
 common.without.Method4 - subset(common, Method!=4)
 xyplot(MeanBxg ~ PercentVarExplained | bdg.f * bdx.f,
 data=common.without.Method4,
 groups=Method.f, type=l,  auto.key=T)
 
 Ross Darnell
 
 -Original Message-
 From: [EMAIL PROTECTED]
 [mailto:[EMAIL PROTECTED] On Behalf Of Gen
 Sent: Thursday, 30 August 2007 2:51 PM
 To: r-help@stat.math.ethz.ch
 Subject: [R] customizing the color and point shape for each line drawn
 using lattice's xyplot
 
 
 Description of what I am trying to do:
 I am using the xyplot code below to plot the variable MeanBxg
against
 the
 variable PercentVarExplained for all 9 possible combinations of
 variables
 bdg and bdx.  Within each of these 9 scenarios I am plotting a
 separate
 line for each of up to 9 different methods that I used to estimate the
 variable MeanBxg. These methods are identified by the numeric variable
 called Method.  Giving me one plot with 9 figures and each of the
 figures
 contains 9 lines. 
 
 My problem arises because I would like to repeat the creation of this
 plot 8
 times, in each instance only a subset (eg 6) of the 9 methods are used
 (a
 different subset each time). 
 
 What I can't figure out:
 I would like to learn how to specify the exact line color that
 corresponds
 to each method such that Method==1 will always be represented by the
 same
 color (in every plot that it appears in).  Where two methods that I
used
 were of the same family of methods (say method==1 and method==2 made
the
 same assumptions about the data)  I would like to, if possible,
 represent
 the two methods using the same color and distinguish them by the
symbol
 used
 to represent points on the line. 
 
 My code as it currently stands:
 xyplot(MeanBxg ~ PercentVarExplained | bdg.f * bdx.f, data=common,
 groups=common$Method.f, type=l, subset= Method!=4, auto.key=T)
 
 As the code is, the default colors assigned are repeated causing
 different
 methods to be represented by the same color with no way to distinguish
 them
 (I have not succeeded in plotting lines and points simultaneously).  
 
 Side question: When I subset the data to particular methods, is there
a
 way
 to remove the excluded methods from the key as well? (in my code
 Method is
 a numeric variable, and Method.f corresponds to the lengthy
 descriptions
 of each method for the purpose of the key)
 
 Thank you very much for your help. 
 Genevieve
 
 
 
 -- 
 View this message in context:

http://www.nabble.com/customizing-the-color-and-point-shape-for-each-lin
 e-drawn-using-lattice%27s-xyplot-tf4351934.html#a12400517
 Sent from the R help mailing list archive at Nabble.com.
 
 __
 R-help@stat.math.ethz.ch 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.
 
 __
 R-help@stat.math.ethz.ch 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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-- 
View this message in context:
http://www.nabble.com/customizing-the-color-and-point-shape-for-each-lin
e-drawn-using-lattice%27s-xyplot-tf4351934.html#a12409939
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Re: [R] Conditional subsetting

2007-08-07 Thread Ross Darnell

Assuming *A* animal can only be in one location at any one time, I don't 
understand how once you have selected the location nearest 12pm how you can 
select based on the type of location?
Do you mean to select on location before timei.e. from the best location 
visited that day which was closest to 12pm?

Perhaps for condition 2  for a animal which.min(time-1200) (replace 1200 with 
properly defined timestamp representing 12:00pm)

Ross Darnell
  


-Original Message-
From: [EMAIL PROTECTED] on behalf of Tim Sippel
Sent: Wed 08-Aug-07 9:37 AM
To: r-help@stat.math.ethz.ch
Subject: [R] Conditional subsetting
 
Hello-

Upon searching the email archives and reading documentation I haven't found
what I'm looking for.  I have a dataset with a time/date stamp on a series
of geographic locations (lat/lon) associated with the movements of animals.
On some days there are numerous locations and some days there is only one
location.  Associated with each location is an indication that the quality
of the location is either good, poor, or unknown.  For each animal, I
want to extract only one location for each day.  And I want the location
extracted to be nearest to 12pm on any given day, and highest quality
possible.  

So the order of priority for my extraction will be: 1. only one location per
animal each day; 2. the location selected be as close to 12pm as possible;
3. the selected location comes from the best locations available (ie. take
from pool of good locations first, or select from poor locations if a
good location isn't available, or unknown if nothing else is available).


 

I think aspect of this task that has me particularly stumped is how to
select only one location for each day, and for that location to be a close
to 12pm as possible.  

 

An example of my dataset follows:

 



DeployID

 

Date.Time

 

LocationQuality

Latitude

Longitude


STM05-1

 

28/02/2005 17:35

 

Good

-35.562

177.158


STM05-1

 

28/02/2005 19:44

 

Good

-35.487

177.129


STM05-1

 

28/02/2005 23:01

 

Unknown

-35.399

177.064


STM05-1

 

01/03/2005 07:28

 

Unknown

-34.978

177.268


STM05-1

 

01/03/2005 18:06

 

Poor

-34.799

177.027


STM05-1

 

01/03/2005 18:47

 

Poor

-34.85

177.059


STM05-2

 

28/02/2005 12:49

 

Good

-35.928

177.328


STM05-2

 

28/02/2005 21:23

 

Poor

-35.926

177.314

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

 

 

 

 

 

 

 

 

 

Many thanks for your input.  I'm using R 2.5.1 on Windows XP.  

 

Cheers,

 

Tim Sippel (MSc)

School of Biological Sciences

Auckland University

Private Bag 92019

Auckland 1020

New Zealand

+64-9-373-7599 ext. 84589 (work)

+64-9-373-7668 (Fax)

+64-21-593-001 (mobile)

 


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Re: [R] problem with reading data files with different numbers of lines to skips

2007-08-02 Thread Ross Darnell

You could read the file and test each line (try readline()) but you need some 
rule to distinguish between text lines and data lines. You could then reread 
the file with the number of skip lines defined.

Ross Darnell 

-Original Message-
From: [EMAIL PROTECTED] on behalf of Tom Cohen
Sent: Fri 03-Aug-07 7:14 AM
To: r-help@stat.math.ethz.ch
Subject: [R] problem with reading data files with different numbers of lines
to skips
 
Dear  List, 
   
  I have 30 data files with different numbers of lines (31 and 33) that I want 
to skip before reading the files. If I use the skip option I can only choose 
either to skip 31 or 33 lines. The data files with 31 lines have no blank rows 
between the lines and the header row. How can I read the files without manually 
checking which files have 31 respectively 33 lines ?  The only text line I want 
to keep is the header.
   
  Thamks for your help,
  Tom
   
   
  for (i in 1:num.files) {
   a-read.table(file=data[i],
  ,header=T,skip=31,sep='\t',na.strings=NA) 
  
  }
   
   
   

   
-
Går det långsamt? Skaffa dig en snabbare bredbandsuppkoppling.

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Re: [R] Convert string to list?

2007-07-26 Thread Ross Darnell
Manuel

Jim's may be what you want-- a list of numerics with names P, T and Q or
a list of character strings?

 str - P = 0.0, T = 0.0, Q = 0.0

 str(as.vector(unlist(strsplit(str,,)),mode=list))
List of 3
 $ : chr P = 0.0
 $ : chr  T = 0.0
 $ : chr  Q = 0.0



-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of jim holtman
Sent: Friday, 27 July 2007 11:20 AM
To: Manuel Morales
Cc: r-help
Subject: Re: [R] Convert string to list?

Is this what you want:

 str - P = 0.0, T = 0.0, Q = 0.0
 x - eval(parse(text=paste('list(', str, ')')))
 str(x)
List of 3
 $ P: num 0
 $ T: num 0
 $ Q: num 0



On 7/26/07, Manuel Morales [EMAIL PROTECTED] wrote:
 Let's say I have the following string:

 str - P = 0.0, T = 0.0, Q = 0.0

 I'd like to find a function that generates the following object from
 'str'.

 list(P = 0.0, T = 0.0, Q = 0.0)

 Thanks!

 --
 http://mutualism.williams.edu

 __
 R-help@stat.math.ethz.ch mailing list
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 PLEASE do read the posting guide
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-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?

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Re: [R] Convert string to list?

2007-07-26 Thread Ross Darnell
Is this what your want?


as.vector(unlist(strsplit(str,,)),mode=list)


Ross Darnell

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Manuel Morales
Sent: Friday, 27 July 2007 10:39 AM
To: r-help
Subject: [R] Convert string to list?

Let's say I have the following string:

str - P = 0.0, T = 0.0, Q = 0.0

I'd like to find a function that generates the following object from
'str'.

list(P = 0.0, T = 0.0, Q = 0.0)

Thanks!

-- 
http://mutualism.williams.edu

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Re: [R] questions on lme function

2007-07-04 Thread Dr Ross Darnell
Ana

You are estimating a random coefficient model on 5 individuals (mean 
and variance). Are you sure this is wise?

Ross Darnell 

- Original Message -
From: Ana Conesa [EMAIL PROTECTED]
Date: Thursday, July 5, 2007 1:21 am
Subject: [R] questions on lme function
 
 Dear list,
 
 I am using the lme funcion to fit a mixed model for the time response
 of a number of physiological variables. The random variable would be
 the individual on which physiological variables are measured at
 different time points. I have 4 time points, 5 individuals and 3
 replicates per condition (time/individual),  and I would like to fit
 a quadratic model on time. The model I am using is
 
  mm - lme(myvar ~ time + time2, random= ~ time|individual,
 data=clinical)
 
 being time2 = time*time
 
 I have a number of questions
 
 1) I am not very sure the random effect is correctly modeled. 
 Would I
 need to include the time2 variable aswell?
 
 2) I would like to extract the F statistics of the model, and I do
 not find a function for this. Is this possible?
 
 3) depending of the variable I take, I frequently obtain a
 convergence error as a result of the lme funcion. Any ideas on what
 to do to improve convergence?
 
 Thank you
 
 Ana Conesa, PhD
 Centro de Investigacion Principe Felipe
 Avda. Autopista Saler 16 46013 Valencia
 http://bioinfo.cipf.es
 
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Re: [R] Log-likelihood function

2007-05-02 Thread Ross Darnell

Alternatively  generate the log-likelihood using the sum(dpois(y,
fitted(model), log = TRUE))


Regards

Ross Darnell


Doxastic wrote:
 
 You're right.  I do need to learn more.  I never learned null/residual
 deviance.  I know the deviance is equivalent to an anova decompostion. 
 But I've never dealt with it seperated like this.  
 
 I understand deviance as the difference between two model's log-likelihood
 difference between them and the most complex.  I want to compare two
 models that are not the most complex.  That is why I wanted the
 log-likelihood.  
 
 I am using the poisson distribution because my response is count data, so
 the link is the log.  If the deviance in R is computed by comparing the
 fitted model against the most saturated (which would make sense).  Then
 yes, I can use that.  I just picked the log-likelihood because I'm
 comparing two models.  And that's the best way.  But, it's equivalent if R
 compares the fitted to the most complex.
 
 I assumed the deviance print out tested the fitted model against the least
 complex.  This tests whether the current model parameters can be dropped
 (that's what I thought the null deviance meant).  I'm not sure what the
 residaul deviance means though.  
 
 My main concern is why the likelihood functions differed between SAS and
 R.  If anyone has encountered this or understands why, I would appreciate
 some help.
 
 
 
 Prof Brian Ripley wrote:
 
 I think you need to learn about deviances, which R does print.
 
 Log-likelihoods are only defined up to additive constants.  In this case 
 the conventional constant differs if you view this as a Poisson or as a 
 product-multinomial log-linear model, and R gives you the log-likelihood 
 for a Poisson log-linear model (assuming you specified family=poisson). 
 However, deviances and differences in log-likelihoods do not depend on 
 which.
 
 More details and worked examples can be found in MASS (the book, see the 
 FAQ), including other ways to fit log-linear models in R.
 
 
 On Tue, 1 May 2007, someone ashamed of his real name wrote:
 
 I've computed a loglinear model on a categorical dataset.  I would like
 to
 test whether an interaction can be dropped by comparing the
 log-likelihoods
 from two models(the model with the interaction vs. the model without).
 Since R does not immediately print the log-likelihood when I use the
 glm
 function, I used SAS initially.  After searching for an extracting
 function,
 I found one in R.  But, the log-likelihood given by SAS is different
 from
 the one given by R.  I'm not sure if the logLik function in R is
 giving me
 something I don't want.  Or if I'm misinterpreting the SAS output.  Can
 anyone help?

 
 -- 
 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
 
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[R] Lattice plots of the form xyplot(y1+y2~x)

2006-11-17 Thread Ross Darnell
I would appreciate help trying
to set different plot types  in a lattice plot with multiple responses e.g.

xyplot(y+fval~x)

but  have y as points and fval as a line.

I have tried

xyplot(y+fval~x,type=c(p,l))

but this results in both plots having both types.

Thanks

Ross Darnell
University of Queensland, AUSTRALIA

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[R] MASS4 page 360 cumulative hazard plot

2006-10-15 Thread Ross Darnell
I cannot reproduce Fig. 13.2 in MASS4.

 plot(gehan.surv,fun='cloglog')
Warning message:
2 x values = 0 omitted from logarithmic plot in: xy.coords(x, y, 
xlabel, ylabel, log)

and the x-axis is badly scaled.

I was wondering if someone can help


Regards
Ross Darnell

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Re: [R] Sweave and the [ function

2006-09-05 Thread Ross Darnell
Hi Vincent

This would seem logical but in this case doesn't work.
It doesn't seem to be a Sweave problem (feature) at all  but within R as 
Hadley stated.
Within R try

  quote(women[1])
women[1]

now try

  quote([(women,1))
women[1]

So it's parsed and normalised (there's a familiar term); in this case 
to women[1] before its quoted.

Curiously in the R Language Definition Guide in 10.4.3  it states

R has three indexing constructs, two of which are syntactically similar 
although with somewhat
different semantics:
object [ arg1, .. , argn ]
object [[ arg1, .. , argn ]]
The object can formally be any valid expression, but it is understood to 
denote or evaluate
to a subsettable object. The arguments generally evaluate to numerical 
or character indices,
but other kinds of arguments are possible (notably drop = FALSE).
Internally, these index constructs are stored as function calls with 
function name [ respectively
[[.

So I'm lost now. Can some one hand me a  map and compass?
 




Vincent Goulet wrote:
 Le Mardi 5 Septembre 2006 0:03, hadley wickham a écrit :
   
 =
 str(women)
 women$height
 women[,1]
 [(women,1)
 @

 to show the equivalence of  three methods of extracting an element from
 a data.frame.

 However Sweave returns the last of these as

 women[1]

 in the S input chunk

 How can I force it not to do this and return [(women,1)
   
 I don't think you can.  Sweave parses your R code and from then on
 uses the internal R representation.  R normalises the parse tree in
 certain ways (eg. strips comments, formats source code, and clearly
 normalises some function calls).  Since sweave uses this, and not the
 original text, I don't think there is anyway to get around this,
 unless there is some trick during parsing.

 (And don't forget women[[1]])

 Hadley
 

 So here's a workaround (untested):

 echo=TRUE, eval=TRUE=
 str(women)
 women$height
 women[,1]
 @
 echo=TRUE, eval=FALSE=
 [(women,1)
 @
 echo=FALSE, eval=TRUE=
 [(women,1)
 @

 I often end up doing similar things.

 HTHVincent



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[R] Sweave and the [ function

2006-09-04 Thread Ross Darnell
I am wanting to use the [ operator in an S-chunk, e.g.


=
str(women)
women$height
women[,1]
[(women,1)
@

to show the equivalence of  three methods of extracting an element from 
a data.frame.

However Sweave returns the last of these as

women[1]

in the S input chunk

How can I force it not to do this and return [(women,1)

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[R] Lattice plot of multiply-nested data

2006-05-09 Thread Ross Darnell
I would like to replicate Figure 3.12 from Pinheiro and Bates's Mixed 
Effects Models in S and S-PLUS
but I would like to plot both the average line as well as the individual 
sites lines on the same panel.
I did try modifying the panel function but I cannot seem to  get it  as  
described.

I would appreciate any suggestions

Ross Darnell
University of Queensland

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[R] Coefficients for aliased models

2006-04-24 Thread Ross Darnell
I find the reporting of aliased terms in class lm objects as little 
inconsistent.

The best way to show  this is to give an example.

X - mvrnorm(10,c(0,0),Sigma=matrix(c(1,0.5,0.5,1),nrow=2))
Xnew - as.data.frame(cbind(X,X[,2])) # make copy of X[,2]
names(Xnew) - c(y,X,Xcopy)
model - lm(y~X+Xcopy,data=Xnew)
coef(model)  # reports NA for Xcopy estimate
summary(model) # ditto
coef(summary(model)) # drops NA for Xcopy estimate

Is this intentional? Is there a way of extracting the coefficient table 
from the summary output with the aliased term included?

Many thanks

Ross Darnell

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[R] Calculation of r.squared for linear model with offset

2006-04-09 Thread Ross Darnell
R^2 for a model is usually defined as 1-RSS/TSS where TSS is the SS 
about the mean and RSS is the residual SS from the model.

Consider the model in R

z - runif(20)
y - z+rnorm(20)
my.model - lm(y~offset(z))
summary(my.model)$r.squared

Here the RSS is equivalent to the TSS and
gives 0 when it should (IMHO and a few others perhaps) be

1 - RSS/TSS(corrected for the mean only)

RSS = sum(resid(my.model)^2)
TSS = sum((y-mean(y))^2)

Have I missed this somewhere in the FAQ's or elsewhere?

Regards
Ross Darnell

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[R] Sweave: How can I include S input in paragraph mode

2005-12-01 Thread Ross Darnell
Sweavers

As the title suggests I would appreciate any help to include S code in
ordinary paragraph mode. I can use the textsl font but is isn't the
same.

Thanks

Ross Darnell

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[R] Translating lme model call to lme4

2005-09-12 Thread Ross Darnell
I would appreciate help translating the following lme model to an lmer 
function.

lme(lognrms ~ Group*Rotation*muscle*side*support*arms,
 random=~1|Subject/Stratum2/rep, data=Data)



Many thanks

Ross Darnell
[EMAIL PROTECTED]

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[R] anova.lmlist output change

2005-07-13 Thread Ross Darnell
R-colleagues

I have adapted the anova.lmlist function to use the model object name as 
the first column in the output instead of the string Model n.

If there is general agreement can the change be implemented into the 
stats package?

Regards

Ross Darnell
-- 
University of Queensland, Brisbane QLD 4072 AUSTRALIA
Email: [EMAIL PROTECTED]

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Re: [R] A suggestion for predict function(s)

2005-04-13 Thread Ross Darnell
Liaw, Andy wrote:
I must respectfully disagree.  Why carry extra copies of data arround?  This
is probably OK for small to medium sized data, but definitely not for large
data.
Besides, in your example, it may do different things depending on whether
newdata is supplied:  model.matrix is not necessarily the same as the
original data frame.  You need a bit more work to get the right model.matrix
that correspond to the newdata.  It's not clear to me whether you want to
return model matrix or model frame, but in either case it's not sufficient
to just use `newdata'.
Andy

From: Ross Darnell
Maybe a useful addition to the predict functions would be to 
return the 
values of the predictor variables. It just (unless there are 
problems) 
requires an extra line. I have inserted an example below.

predict.glm -
  function (object, newdata = NULL, type = c(link, response,
  terms), se.fit = FALSE, 
dispersion = NULL, terms = NULL,
na.action = na.pass, ...)
{
  type - match.arg(type)
  na.act - object$na.action
  object$na.action - NULL
  if (!se.fit) {
if (missing(newdata)) {
  pred - switch(type, link = object$linear.predictors,
 response = object$fitted, terms = 
predict.lm(object,
 se.fit = 
se.fit, scale 
= 1, type = terms,
 terms = terms))
  if (!is.null(na.act))
pred - napredict(na.act, pred)
}
else {
  pred - predict.lm(object, newdata, se.fit, scale = 1,
 type = ifelse(type == link, 
response, type),
 terms = terms, na.action = na.action)
  switch(type, response = {
pred - family(object)$linkinv(pred)
  }, link = , terms = )
}
  }
  else {
if (inherits(object, survreg))
  dispersion - 1
if (is.null(dispersion) || dispersion == 0)
  dispersion - summary(object, dispersion = 
dispersion)$dispersion
residual.scale - as.vector(sqrt(dispersion))
pred - predict.lm(object, newdata, se.fit, scale = 
residual.scale,
   type = ifelse(type == link, 
response, type),
   terms = terms, na.action = na.action)
fit - pred$fit
se.fit - pred$se.fit
switch(type, response = {
  se.fit - se.fit * abs(family(object)$mu.eta(fit))
  fit - family(object)$linkinv(fit)
}, link = , terms = )
if (missing(newdata)  !is.null(na.act)) {
  fit - napredict(na.act, fit)
  se.fit - napredict(na.act, se.fit)
}
predictors - if (missing(newdata)) model.matrix(object) 
else newdata
pred - list(predictors=predictors,
 fit = fit, se.fit = se.fit,
 residual.scale = residual.scale)
  }
  pred

#__ end of R code

Ross Darnell
--
School of Health and Rehabilitation Sciences
University of Queensland, Brisbane QLD 4072 AUSTRALIA
Email: [EMAIL PROTECTED]
Phone: +61 7 3365 6087 Fax: +61 7 3365 4754  Room:822, 
Therapies Bldg.
http://www.shrs.uq.edu.au/shrs/school_staff/ross_darnell.html

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[R] A suggestion for predict function(s)

2005-04-12 Thread Ross Darnell
Maybe a useful addition to the predict functions would be to return the 
values of the predictor variables. It just (unless there are problems) 
requires an extra line. I have inserted an example below.

predict.glm -
  function (object, newdata = NULL, type = c(link, response,
  terms), se.fit = FALSE, 
dispersion = NULL, terms = NULL,
na.action = na.pass, ...)
{
  type - match.arg(type)
  na.act - object$na.action
  object$na.action - NULL
  if (!se.fit) {
if (missing(newdata)) {
  pred - switch(type, link = object$linear.predictors,
 response = object$fitted, terms = predict.lm(object,
 se.fit = se.fit, scale 
= 1, type = terms,
 terms = terms))
  if (!is.null(na.act))
pred - napredict(na.act, pred)
}
else {
  pred - predict.lm(object, newdata, se.fit, scale = 1,
 type = ifelse(type == link, response, type),
 terms = terms, na.action = na.action)
  switch(type, response = {
pred - family(object)$linkinv(pred)
  }, link = , terms = )
}
  }
  else {
if (inherits(object, survreg))
  dispersion - 1
if (is.null(dispersion) || dispersion == 0)
  dispersion - summary(object, dispersion = dispersion)$dispersion
residual.scale - as.vector(sqrt(dispersion))
pred - predict.lm(object, newdata, se.fit, scale = residual.scale,
   type = ifelse(type == link, response, type),
   terms = terms, na.action = na.action)
fit - pred$fit
se.fit - pred$se.fit
switch(type, response = {
  se.fit - se.fit * abs(family(object)$mu.eta(fit))
  fit - family(object)$linkinv(fit)
}, link = , terms = )
if (missing(newdata)  !is.null(na.act)) {
  fit - napredict(na.act, fit)
  se.fit - napredict(na.act, se.fit)
}
predictors - if (missing(newdata)) model.matrix(object) else newdata
pred - list(predictors=predictors,
 fit = fit, se.fit = se.fit,
 residual.scale = residual.scale)
  }
  pred

#__ end of R code

Ross Darnell
--
School of Health and Rehabilitation Sciences
University of Queensland, Brisbane QLD 4072 AUSTRALIA
Email: [EMAIL PROTECTED]
Phone: +61 7 3365 6087 Fax: +61 7 3365 4754  Room:822, Therapies Bldg.
http://www.shrs.uq.edu.au/shrs/school_staff/ross_darnell.html
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[R] Histogram without common borders

2004-07-19 Thread Ross Darnell
Is it possible to produce a histogram directly using the hist()
function with the common borders removed?

It can be done by plotting the histogram object using type 's'teps.

my.hist - hist(x,plot=FALSE)
plot(my.hist$breaks,c(0,my.hist$counts),type='s')

I would appreciate help

Ross Darnell 
-- 
University of Queensland, Brisbane QLD 4067 AUSTRALIA
Email: [EMAIL PROTECTED]
Phone: +61 7 3365 6087 Fax: +61 7 3365 4754
http://www.shrs.uq.edu.au/shrs/school_staff/ross_darnell.html

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[R] WinMenu's question

2004-06-01 Thread Ross Darnell
I am using the Windows menu functions below which will work on the
first pass, but if I repeat the same script I cannot get the
WinMenuAddItem to work. This is a problem if I change the menu
structure and reread the source code I am forced to quit and restart Rgui.

try.menu - function(){
  OS - .Platform$OS.type
  GUI - .Platform$GUI
  if (!(OS == windows  GUI == Rgui)) return(Sorry, you must be running R using 
Rgui.exe on MS Windows)
  try(winMenuDelItem('EMG/Graphics','Plot.trace'))
  try(winMenuDel('EMG/Graphics'))
  try(winMenuDel(EMG))
  winMenuAdd(EMG)
  winMenuAdd(EMG/Graphics)
  winMenuAddItem(EMG/Graphics,Plot trace,plot.trace())
}
plot.trace - function(){
  x - eval(parse(text=trace.dialog()))
  plot(x,type=l)
  invisible()
}


Help much appreciated

Ross Darnell
-- 
University of Queensland, Brisbane QLD 4067 AUSTRALIA
Email: [EMAIL PROTECTED]
Phone: +61 7 3365 6087 Fax: +61 7 3365 4754
http://www.shrs.uq.edu.au/shrs/school_staff/ross_darnell.html

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[R] Frequent crash printing graphics windows and wavethresh

2003-12-08 Thread Ross Darnell

I often have R (1.8.1) crash after I generate several graphics windows using
windows() or X11(), print a graphics window and then rerun the same
script. A windows message comes up saying Program error Rterm.exe .. 
(I can get the same problem using Rgui.)

Xemacs tells me 
Process R trace trap at time  and date

The entry in the Dr Watson logs starts with


Application exception occurred:
App:  (pid=134697032)
When: 26/11/2002 @ 21:12:10.057
Exception number: c005 (access violation)


The situation in which I can consistently produce this is when I am
using the wavethresh3 dll and associated functions. I have tried to
generate the same problem without using wavelet functions (just
producing several graphics windows with plots of random numbers) but
cannot reproduce this problem consistently from a new session.

I was wondering if anyone else is experiencing this problem

Regards

Ross Darnell
-- 
University of Queensland, Brisbane QLD 4067 AUSTRALIA
Email: [EMAIL PROTECTED]

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Re: [R] help with nomogram function

2003-11-06 Thread Ross Darnell

Frank Harrell wrote
 
 On Wed, 05 Nov 2003 09:22:34 +1000
 Ross Darnell [EMAIL PROTECTED] wrote:
 
  I have fitted a logistic regression model
  
   failed.lr2$call
  lrm(formula = failed ~ Age + task2 + Age:task2, data = time.long, 
  na.action = na.omit)
 
 Use Age*task2 and omit na.action as na.omit is the default
 
  
  using the Design package functions and would like to generate a
  nomogram from this model.
  
  the datadist information is generated and stored in
  
   ddist
  time.long$Age time.long$task2
  Low:effect 45NA
  Adjust to  56   both.foam
  High:effect68NA
  Low:prediction 21   both.foam
  High:prediction80   right
  Low20   both.foam
  High   80   right
 
 This looks most strange.  You did not include the original code but I
 suspect you had $ in a term.  $ should not appear in column headings
 above.  Design wants you to use data= or attach, and avoid $ in terms.
 
 
  
  Values:
  
  time.long$task2 : both.foam left right 
   
  
  The model fitted and then when I try the nomgram function
  
   nomogram(failed.lr2)
  Error in value.chk(at, i, NA, -nint, Limval, type.range = full) : 
  variable Age does not have limits defined by datadist
   
  
  I get an error. The NA values in ddist seem to be the problem but I
  don't understand the datadist information.
  

I tried using the data argument in datadist

 names(my.data)
[1] subject Age failed  task   
 ddist - datadist(Age,task,data=my.data)
Error in datadist(Age, task, data = my.data) : 
Object Age not found


Strange.

Thanks
Ross Darnell


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[R] help with nomogram function

2003-11-04 Thread Ross Darnell
I have fitted a logistic regression model

 failed.lr2$call
lrm(formula = failed ~ Age + task2 + Age:task2, data = time.long, 
na.action = na.omit)

using the Design package functions and would like to generate a
nomogram from this model.

the datadist information is generated and stored in

 ddist
time.long$Age time.long$task2
Low:effect 45NA
Adjust to  56   both.foam
High:effect68NA
Low:prediction 21   both.foam
High:prediction80   right
Low20   both.foam
High   80   right

Values:

time.long$task2 : both.foam left right 
 

The model fitted and then when I try the nomgram function

 nomogram(failed.lr2)
Error in value.chk(at, i, NA, -nint, Limval, type.range = full) : 
variable Age does not have limits defined by datadist
 

I get an error. The NA values in ddist seem to be the problem but I
don't understand the datadist information.

Can anyone help explain why this is failing.

Thanks

Ross Darnell

-- 

University of Queensland, Brisbane QLD 4067 AUSTRALIA
Email: [EMAIL PROTECTED]
Phone +61 7 3365 6087
http://www.shrs.uq.edu/shrs/school_staff/ross_darnell.html

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[R] R workshop, Qld Australia

2003-08-06 Thread Ross Darnell
Need some help with R?

An R workshop, lead by John Maindonald, is planned for the 2nd October
at the University of Southern Queensland, Toowoomba, Australia. The
workshop is being organised by the Queensland branch of the
Statistical Society of Australia as part of their conference.

Anyone interested in attending can find out more by looking at 

http://www.sci.usq.edu.au/staff/dunn/qstatconf/workshops.html

-- 
Ross Darnell
Organising committee
Email: [EMAIL PROTECTED]

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Re: [R] Specifying an lme model

2003-07-15 Thread Ross Darnell
Thanks for the help.

Sorry but now comes the second question. What we have now assumes
equal within-subject variances. How can I fit separate (pooled)
within-subject variances for each group (similar to an unequal
variance t-test) and test if this is better than the existing constant
within-subject variance.

Many thanks

Ross
 
Douglas Bates [EMAIL PROTECTED] writes:

 Ross Darnell [EMAIL PROTECTED] writes:

 I would like some advice on how if possible, to test the following
 
  I have subjects each measured several times. The subjects are sampled
  from 3 subpopulations (groups). The question is Is the 
  between-subject variance the same for the three groups?
 
 The null model is 
 
 lme0 - lme(y~group,random=~1|subject)
 
 I did think that the model that defined a specific between-subject
 variance for each group was
 
 update(lme0,.~., weights=varIdent(form=~1|group))
 
 but I am not sure.

 I think you have it right.  You should then compare the two fitted
 models using the anova generic, which will provide a likelihood ratio
 test statistic and a p-value based on a chi-squared reference
 distribution.  Regard the p-value as an approximation.




-- 
Ross Darnell
School of Health and Rehabilitation Sciences
University of Queensland, Brisbane QLD 4067 AUSTRALIA
Email: [EMAIL PROTECTED]
Phone +61 7 3365 6087
http://www.uq.edu.au/~uqrdarne/

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[R] Specifying an lme model

2003-07-14 Thread Ross Darnell
I would like some advice on how if possible, to test the following

 I have subjects each measured several times. The subjects are sampled
 from 3 subpopulations (groups). The question is Is the 
 between-subject variance the same for the three groups?

The null model is 

lme0 - lme(y~group,random=~1|subject)

I did think that the model that defined a specific between-subject
variance for each group was

update(lme0,.~., weights=varIdent(form=~1|group))

but I am not sure.

I would appreciate any help.

Ross Darnell

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RE: [R] equivalence test

2003-06-26 Thread Ross Darnell
Hi,
   is it possible to do an equivalence test on paired quantitative datas 
in R? Is there a way to calculate sample size for such tests?

I've tried to find some documentation on that subject but I was 
unsuccessfull. 
I'll be happy with any links on equivalence test. If such a test does'nt 
exist in R, i'll do it manually if I find a method to do so.

Best regards

Blaise

The sample size for an equivalence trial with normally distributed
outcomes can be calculated by

n - 2 * s^2 / delta^2 * (qnorm(alpha/2) + qnorm(beta/2))^2

s = standard deviation
delta = clinically important difference
alpha = Type I error
beta = Type II error


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Ross Darnell

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[R] Re: Finding missing data patterns

2003-02-02 Thread Ross Darnell

The norm package of Joe Schafer can be used. It has a function called
'prelim' (or very similar) that does this.

Regards
Ross Darnell

Email: [EMAIL PROTECTED]

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[R] Searching for glmmNQ

2003-01-07 Thread Ross Darnell

I cannot find the glmmNQ function in the MASS package (or anywhere else I have tried) 
mentioned on page 296 of MASS4.

I would appreciate directions.
Thanks
-- 
Ross Darnell

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