Re: [R] define colors for groups in lattice xyplot

2010-09-03 Thread Dennis Murphy
Hi: The 'easy' solution is to define the colors corresponding to the genotypes directly in lattice: xyplot( result ~ time | location, data=dataset, groups=genotype, pch=19, type=b, col = c('red', 'green', 'blue')) The problem with trying to use color as a variable to 'match' to genotype is that

Re: [R] Generation of uniform random numbers

2010-09-03 Thread Dennis Murphy
Hi: Here's a slightly different approach, using both mapply() in base (a la David) and mlply() in plyr. My thought was to put the arguments together into a three column data frame; the names were chosen to correspond to the first three arguments of runif(): params - data.frame(n =

Re: [R] R program google search

2010-09-03 Thread Dennis Murphy
Hi: Do you mean something like RSiteSearch('loess predict') [opens up a web page with 53 matches to the request] or package(sos) findFn('multiple imputation') ? If not, could you be more specific about what you're after? HTH, Dennis On Fri, Sep 3, 2010 at 2:23 PM, Waverley @ Palo Alto

Re: [R] reshape to wide format takes extremely long

2010-09-02 Thread Dennis Murphy
Hi: I did the following test using function ddply() in the plyr package on a toy data frame with 5 observations using five studies, 20 subjects per study, 25 cycles per subject, five days per cycle and four observations by type per day. No date-time variable was included. # Test data frame

Re: [R] reshape to wide format takes extremely long

2010-09-02 Thread Dennis Murphy
Hi: Thanks, David and Thierry. I knew what I did was inefficient, but I'm not very adept with cast() yet. Thanks for the lesson! The time is less than half without the fun = mean statement, too. On my system, the timing of David's call was 2.06 s elapsed; with Thierry's, it was 4.88 s. Both big

Re: [R] Error: could not find function ad.test

2010-09-02 Thread Dennis Murphy
Hi: One option to search for functions in R is to download the sos package: library(sos) findFn('Anderson-Darling') On my system (Win 7), it found 51 matches. The two likeliest packages are nortest and ADGofTest. To answer your question, nortest still exists on CRAN. I can't comment on Ubuntu,

Re: [R] Writing My Own Function to Use With aggregate

2010-09-01 Thread Dennis Murphy
Hi: aggregate() is not well suited for summarization when the summary function takes multiple input arguments. Better choices for this type of summary are packages plyr, as David mentioned, and data.table. Here's a toy example to illustrate. The fake data contain two grouping variables as

Re: [R] diamond/triangle plot

2010-09-01 Thread Dennis Murphy
Hi: As a statistician and long time baseball addict, I concur wholeheartedly with David that: ...you've got to admit that was one gawdawful graph. Firstly, the areas are not proportional to the values; this is a common graphics mistake. (For example, compare baserunning to power - is the area

Re: [R] different interface to by (tapply)?

2010-08-30 Thread Dennis Murphy
Hi: You've already gotten some good replies re aggregate() and plyr; here are two more choices, from packages doBy and data.table, plus the others for a contained summary: key - c(1,1,1,2,2,2) val1 - rnorm(6) indf - data.frame( key, val1) outdf - by(indf, indf$key, function(x) c(m=mean(x),

Re: [R] New to R

2010-08-30 Thread Dennis Murphy
Hi: Try this: library(sos) # install from CRAN if you don't have it findFn('imputation') I got 285 hits. That should be enough to get you started. Here's a recent paper about how to use sos from the R Journal (Dec. 2009):

Re: [R] Help With Post-hoc Testing

2010-08-30 Thread Dennis Murphy
Hi: See below. On Mon, Aug 30, 2010 at 2:21 PM, Bruce Johnson bruce.ejohn...@verizon.netwrote: I am trying to do post-hoc tests associated with a repeated measures analysis with on factor nested within respondents. The factor (SOI) has 17 levels. The overall testing is working fine, but I

Re: [R] reordering levels error

2010-08-30 Thread Dennis Murphy
Hi: I don't know if this is exactly what you wanted, but here goes. I made a few adjustments in the data frame before calling ggplot(): # library(ggplot2) # Reorient the order in which variables appear winter - winter[, c(1, 7, 3, 6, 4, 5, 2)] # Get rid of second week 26 at the end winter2 -

Re: [R] How to define new matrix based on an elementary row operation in a single step?

2010-08-28 Thread Dennis Murphy
Hi: Here are some functions for computing elementary matrices so that you can do Gauss elimination the hard way (the easy way is the LU decomposition, but I digress) I wouldn't use these for serious work, since there are no checks for matrix instability, but the essential ideas are there. It

Re: [R] Nestad ANOVA with random Factors

2010-08-27 Thread Dennis Murphy
Hi: I'm kind of wondering why Area and Plot are nested within Day. Are you measuring different areas and different plots on different days? Dennis On Fri, Aug 27, 2010 at 12:43 AM, Pablo R ri...@hotmail.com wrote: Hi, I need a help. I am new in R and I need to run a nested anova with

Re: [R] LFA package

2010-08-27 Thread Dennis Murphy
Hi: To find functions in R for particular tasks, package sos is an invaluable resource: library(sos) findFn('latent factor analysis') produces 72 hits on my system, not all of which are relevant, but at least it gets you in the vicinity of what you're looking for. In addition to sem, it

Re: [R] multivariate distributions

2010-08-27 Thread Dennis Murphy
Hi: One form of a multivariate beta distribution is the Dirichlet, so using package sos, library(sos) # install if necessary u - findFn('Dirichlet distribution') grepFn('Dirichlet distribution', u, column = 'Description', ignore.case = TRUE) reveals about 25 matches, about half of which

Re: [R] Plot bar lines like excel

2010-08-25 Thread Dennis Murphy
Hi: Here's a ggplot2 version of your graph. Since you didn't include the dates, I had to make them up, and it may have some consequence with respect to your times because yours don't appear to be exactly equally spaced. I created two data frames - an 'original' one that contains both series in

Re: [R] lmer() causes segfault

2010-08-25 Thread Dennis Murphy
Hi: Let's start with the data: str(test.data) 'data.frame': 100 obs. of 4 variables: $ StudentID: num 17370 17370 17370 17370 17379 ... $ GroupID : num 1 1 1 1 1 1 1 1 1 1 ... $ Time : num 1 2 3 4 1 2 3 4 1 2 ... $ Score: num 76.8 81.8 89.8 92.8 75.9 ... Both StudentID and

Re: [R] multiple x factors using the sciplot package

2010-08-25 Thread Dennis Murphy
Hi: You can probably do what you want in either ggplot2 or lattice, but I would recommend at least a couple different approaches: (1) Plot individual bar charts by combinations of year and period. This is easy to do in both ggplot2 and lattice: in ggplot2, one would use geom_bar(x) +

Re: [R] Odp: Finding pairs

2010-08-25 Thread Dennis Murphy
Hi: I'm just ideating here (think IBM commercial...) but perhaps a graphical model approach might be worth looking into. It seems to me that Mr. Rhodes is looking for clusters of banks that are under the same ownership umbrella. That information is not directly available in a single variable, but

Re: [R] frequency, count rows, data for heat map

2010-08-25 Thread Dennis Murphy
Hi: Here are a couple of ways to render a basic 2D table. Let's call your input data frame dat: names(dat) - c('samp', 'sequen') ssTab - as.data.frame(with(dat, table(samp, sequen))) ssTab # data frame version samp sequen Freq 1 111abc1 2 1079abc1 3 5576abc1 4

Re: [R] Draw a perpendicular line?

2010-08-25 Thread Dennis Murphy
Hi: The function below plots the line segment between two points A and B as well as the normal from C to AB, with a dot as the intersection point (D), which is returned with the function call. The aspect ratio is kept at one so that the orthogonality between the two lines is not distorted by the

Re: [R] Removing inter-bar spaces in barchart

2010-08-25 Thread Dennis Murphy
Hi: On Wed, Aug 25, 2010 at 11:28 AM, Greg Snow greg.s...@imail.org wrote: Using the barplot function in base graphics you just set space=0, but that function does not have a box.ratio argument which would imply that you are using something else. If you let us know which function (and which

Re: [R] Read data in R

2010-08-24 Thread Dennis Murphy
Hi: Here's one way, but there may be better options: de - read.table(textConnection( + Subject,Sessionblock,LotteryImg,SubjectResp,Pictime,Bidtime,Voltage,ForcedAns + 10816,Session1,75_C2.jpg,No,7095,9548,Mid,Yes + 10816,Session1,25_C1.jpg,No,16629,18130,Low,Yes +

Re: [R] drop unused levels in lattice dotplot axis?

2010-08-24 Thread Dennis Murphy
Hi: This looks to be a step in the right direction, but the resulting panels are all the same size. Perhaps you can build on it... # Solution based on an R-help post by Deepayan Sarkar: # http://tolstoy.newcastle.edu.au/R/e2/help/06/09/1579.html dotplot(A ~ B | C, data=dfr,

Re: [R] Constrained non-linear optimisation

2010-08-24 Thread Dennis Murphy
Hi: A reasonable place to start would be the Optimization task view at CRAN: http://cran.r-project.org/web/views/ HTH, Dennis On Tue, Aug 24, 2010 at 10:47 AM, David Beacham d.beacha...@imperial.ac.ukwrote: I'm relatively new to R, but I'm attempting to do a non-linear maximum likelihood

Re: [R] Plot bar lines like excel

2010-08-24 Thread Dennis Murphy
Hi: This is pretty straightforward to do in ggplot2, but it would be nice to have some data to work with (hint). The job requires processing the two input series and dates with melt() from the reshape package, a couple of opts() to change, proper rotation of the dates, etc. It's easier to show

Re: [R] Memory Issue

2010-08-23 Thread Dennis Murphy
Hi: Are you running 32-bit or 64-bit R? For memory-intensive processes like these, 64-bit R is almost a necessity. You might also look into more efficient ways to invert the matrix, especially if it has special properties that can be exploited (e.g., symmetry). More to the point, you want to

Re: [R] trajectory plot (growth curve)

2010-08-23 Thread Dennis Murphy
Hi: On Mon, Aug 23, 2010 at 4:19 PM, Kingsford Jones kingsfordjo...@gmail.comwrote: Hi Lei, Hope you don't mind I'm moving this back to the list in case others may benefit. Answers below... On Mon, Aug 23, 2010 at 3:37 PM, Lei Liu liu...@virginia.edu wrote: Hi Kingsford, Thanks a

Re: [R] unexpected subset select results?

2010-08-23 Thread Dennis Murphy
And, of course, there's transform, as David knows very well: d - transform(d, c = (a + b) 25) head(d) abzc 1 1 2001 5001 TRUE 2 2 2002 5002 TRUE 3 3 2003 5003 TRUE 4 4 2004 5004 TRUE 5 5 2005 5005 TRUE 6 6 2006 5006 TRUE As far as David's 'wrong way' is concerned, I think he may

Re: [R] trajectory plot (growth curve)

2010-08-23 Thread Dennis Murphy
below. On Mon, Aug 23, 2010 at 6:20 PM, Kingsford Jones kingsfordjo...@gmail.comwrote: On Mon, Aug 23, 2010 at 6:19 PM, Dennis Murphy djmu...@gmail.com wrote: This is an excellent idea - the only snag might occur if someone wants the mean line to be thicker :) fortunately, with your

Re: [R] generate random numbers from a multivariate distribution with specified correlation matrix

2010-08-23 Thread Dennis Murphy
Hi Jane: On Mon, Aug 23, 2010 at 8:05 PM, rusers.sh rusers...@gmail.com wrote: Hi, If you see the link http://www.stata.com/help.cgi?drawnorm, and you can see an example, #draw a sample of 1000 observations from a bivariate standard normal distribution, with correlation 0.5. #drawnorm x

Re: [R] Plotting multiple histograms on same panel

2010-08-23 Thread Dennis Murphy
Hi: On Mon, Aug 23, 2010 at 9:27 AM, LCOG1 jr...@lcog.org wrote: Hey everyone, So i cant figure this out. when using histogram() from lattice instead of hist() i get what i want as far as output. But using histogram i can seem to be able to figure out how to get multiple plots on the

Re: [R] lattice::xyplot() with one factor for points and another for lines - solution

2010-08-22 Thread Dennis Murphy
Hi: Yesterday, I posted a question regarding how to handle different graphical behavior between two factors in xyplot() [package lattice]. After a public and private reply from Deepayan Sarkar, the problem has been resolved nicely, including the addition of a stacked legend for the two factors in

[R] lattice::xyplot() with one factor for points and another for lines

2010-08-21 Thread Dennis Murphy
Hi: In lattice, how does one handle separate graphical behavior for two different factors? In the xyplot below, the objective is to use the levels of one factor to distinguish corresponding shapes and colors, and the levels of the other factor to perform level-wise loess smooths. # Illustrative

Re: [R] t.tests on a data.frame using an apply-type function

2010-08-21 Thread Dennis Murphy
Hi: Henrique's solution is elegant, but if you want to summarize certain features of the test (e.g., the value of the test statistic and its p-value), then here's a different approach using packages reshape and plyr. # Since your data in group C had a sample size of 2, I redid the data frame

Re: [R] How to find residual in predict ARIMA

2010-08-21 Thread Dennis Murphy
Hi: On Sat, Aug 21, 2010 at 9:29 AM, Xiyan Lon xiyan...@gmail.com wrote: Dear All, I have a model to predict time series data for example: data(LakeHuron) Lake.fit - arima(LakeHuron,order=c(1,0,1)) This is what Lake.fit contains (an object of class Arima): names(Lake.fit) [1] coef

Re: [R] graphing plots of plots

2010-08-21 Thread Dennis Murphy
Once you load library(grid) the rest works. Nice job :) Dennis On Sat, Aug 21, 2010 at 1:15 PM, baptiste auguie baptiste.aug...@googlemail.com wrote: Hi, I think you could do it quite easily with lattice, library(lattice) latticeGrob - function(p, ...){ grob(p=p, ..., cl=lattice)

Re: [R] Problem to compute a function with very large numbers

2010-08-20 Thread Dennis Murphy
Hi: I had no problem getting the function to 'run', but it appears the execution time starts to rise dramatically after 1: system.time(x - Wi(100)) user system elapsed 0.030.000.03 system.time(x - Wi(1000)) user system elapsed 0.280.000.28 system.time(x -

Re: [R] xyplot plot with groups

2010-08-20 Thread Dennis Murphy
Hi: Like this? xyplot(y~day|sex, groups=trt, data=dat, type=c('p','g', 'a')) The 'a' stands for average line, or 'connect the averages at different x values'. By using the groups = trt argument, you get one line per treatment group in each panel. A complete list of valid types is given on p.

Re: [R] ifelse command

2010-08-18 Thread Dennis Murphy
Hi: Here's the problem I had with the OP's function: On Wed, Aug 18, 2010 at 4:26 AM, David Winsemius dwinsem...@comcast.netwrote: On Aug 18, 2010, at 5:18 AM, Philip Wong wrote: hello people, I want to make a biased dice using the sample() function and print out the results after n

Re: [R] 'panel.smooth' error

2010-08-18 Thread Dennis Murphy
Hi: This also works: xyplot(incidence ~ year, melanoma, type = c('p', 'smooth')) See p. 75 of the Lattice book for the allowable types. HTH, Dennis On Wed, Aug 18, 2010 at 1:34 PM, Sebastian P. Luque splu...@gmail.comwrote: Hi, The following call: xyplot(incidence ~ year, melanoma,

Re: [R] Different way of aggregating

2010-08-18 Thread Dennis Murphy
Hi: On Wed, Aug 18, 2010 at 4:43 PM, skan juanp...@gmail.com wrote: Hi Usually aggregate is used to calculate things such as the sum of all data on the first day, the sum next day, and so on. But how can I calculate the mean of the first hour of all days, the mean of the second hour of

Re: [R] Lattice xyplots plots with multiple lines per cell

2010-08-17 Thread Dennis Murphy
Here's a lattice solution using some faked data. library(lattice) testdat - data.frame(time = rep(rep(1:10, each = 4), 8), y = rnorm(320), gender = factor(rep(rep(c('F', 'M'), each = 80), 2)), grade = factor(rep(c('1-3', '4-6'),

Re: [R] A question of install R packages

2010-08-17 Thread Dennis Murphy
Hi: I run into this problem occasionally (Windows). My 'solution' is to just reinstall the offending package (it's never failed for me a second time) and then reinstall/update the packages that followed it. Annoying, but no biggie. HTH, Dennis On Mon, Aug 16, 2010 at 8:05 PM, hen chao Chang

Re: [R] Wilcoxon test and grouping factor with multiple levels

2010-08-17 Thread Dennis Murphy
Hi: As the help page for wilcox.test() states (?wilcox.test), the test is meant for one or two groups. Since you have eight groups in your data, the help page for wilcox.test() suggests using kruskal.test() instead, where the latter function applies the Kruskal-Wallis test if your intention is to

Re: [R] plotting functions of chi square

2010-08-17 Thread Dennis Murphy
Hi: On Tue, Aug 17, 2010 at 2:28 PM, maiya maja.zaloz...@gmail.com wrote: Thanks, but that wasn't what I was going for. Like I said, I know how to do a simple chi-square density plot with dchisq(). What I'm trying to do is chi-square / degrees of freedom. Hence rchisq(10,i)/i). How

Re: [R] need of elegant data manipulation

2010-08-16 Thread Dennis Murphy
Hi: Assuming I interpreted your intentions correctly, here are three different ways to get means of Q and T by combinations of dP and n. Your data were read into a data frame named dd. (Note that there are other ways to do this as well...) (1) aggregate(): with(dd, aggregate(cbind(Q, T) ~ dP +

Re: [R] is it possible to map 2 plots(c and d) in a single output plot?

2010-08-14 Thread Dennis Murphy
Hi: Your example doesn't make much sense as stated, but is this what you had in mind? d - ggplot (mtcars, aes(qsec, wt) d + geom_point() + stat_smooth(aes(colour = factor(cyl)), fill=darkgrey, size=2, alpha = 0.2) + scale_colour_discrete(No. cylinders) In this case, the multiple plots

Re: [R] band pass filter

2010-08-14 Thread Dennis Murphy
Try this: library(sos) findFn('bandpass') If necessary, install the package first. I got 24 hits in eight packages. Hopefully one or more of them will be suitable. HTH, Dennis On Sat, Aug 14, 2010 at 8:52 PM, nuncio m nunci...@gmail.com wrote: Hello list, Is there any way to

Re: [R] How to calculate the concentration

2010-08-11 Thread Dennis Murphy
Hi: Try this from package plyr: library(plyr) # function to compute sum of squares f - function(df) with(df, sum((tapply(value, type, sum)/sum(value))^2)) # apply it to each type of food: ddply(data, .(food), conc = f(data)) food type value market_con 1 drink water 5 0.5987654 2

Re: [R] Derivative

2010-08-11 Thread Dennis Murphy
Hi: Try the following: f - function(x) 5*cos(2*x)-2*x*sin(2*x) curve(f, -5, 5) abline(0, 0, lty = 'dotted') This shows rather clearly that your function has multiple roots, which isn't surprising given that it's a linear combination of sines and cosines. To find a specific root numerically, use

Re: [R] Plotting range of values in barplot()

2010-08-06 Thread Dennis Murphy
Hi: As far as I recall, no one has provided a horizontal barchart as a solution, so here's one using lattice: library(lattice) smw.dat-factor(rep(c(Somewhat Disagree, Neutral, Somewhat Agree, Strongly Agree),c(1,2,7,12)), levels=c(Strongly Disagree, Somewhat Disagree, Neutral,

Re: [R] m-estimators

2010-08-06 Thread Dennis Murphy
Hi: Try (install package sos first if necessary): library(sos) findFn('M-estimator') This produced 34 hits on my machine (not quite as productive as Petr's search :), but it identifies a few packages that contain functions for robust estimation. It's also a good way to get familiar with a very

Re: [R] stats::reshape question

2010-08-06 Thread Dennis Murphy
Hi: Is this what you were aiming for? reshape(d,varying=list(c(x1,x2), c(y1,y2)),v.names=c(x,y),dir=long) time x y id 1.11 1 5 1 2.11 2 6 2 1.22 3 7 1 2.22 4 8 2 HTH, Dennis On Fri, Aug 6, 2010 at 10:28 AM, Krishna Tateneni taten...@gmail.comwrote: Hello, A quick

Re: [R] hi!!! guestion!!

2010-08-03 Thread Dennis Murphy
Hi: In addition to the previous replies, there is package R.Matlab and a Matlab/R reference at CRAN by David Hiebeler under Contributed Documentation. HTH, Dennis On Mon, Aug 2, 2010 at 6:57 PM, leepama butch...@hanmail.net wrote: I made some matlab codes... Is there any method to perform

Re: [R] Collinearity in Moderated Multiple Regression

2010-08-03 Thread Dennis Murphy
Hi: On Tue, Aug 3, 2010 at 6:51 AM, haenl...@gmail.com wrote: I'm sorry -- I think I chose a bad example. Let me start over again: I want to estimate a moderated regression model of the following form: y = a*x1 + b*x2 + c*x1*x2 + e No intercept? What's your null model, then? Based on

Re: [R] incorrect number of dimensions

2010-08-03 Thread Dennis Murphy
Hi: This is pure speculation since you didn't provide a minimal data set to test this with, but is it possible that theta is meant to be a parameter *vector*? If so, then you should have eta - theta[1] K - theta[2] The code theta[, 1] means that you want to extract the first column of the

Re: [R] Penalized Gamma GLM

2010-08-03 Thread Dennis Murphy
Hi: Haven't tried it yet personally, but since gamma regression is a special case of generalized linear models, the package glmnet may be of service. Its description reads: Lasso and elastic-net regularized generalized linear models HTH, Dennis On Tue, Aug 3, 2010 at 3:37 PM, Lars Bishop

Re: [R] Adding collumn to existing data frame

2010-08-03 Thread Dennis Murphy
Wouldn't a list be a better object type if the variables you want to add have variable lengths? This way you don't have to worry about nuisances such as NA padding. Just a thought... Dennis On Tue, Aug 3, 2010 at 7:54 PM, Ralf B ralf.bie...@gmail.com wrote: Actually it does -- one has to use

Re: [R] finding max value in a row and reporting colum name

2010-08-01 Thread Dennis Murphy
a - data.frame(x = rnorm(4), y = rnorm(4), z = rnorm(4)) names(a)[apply(a, 1, which.max)] [1] y z z y a x y z 1 -0.8839957 -0.8824065 -0.9343157 2 0.3918695 1.4246880 1.6401349 3 -0.4020719 0.1342691 0.8041808 4 0.1500775 0.8966310 -0.2204660 HTH, Dennis On

Re: [R] (no subject)

2010-07-30 Thread Dennis Murphy
Hi: Avoiding loops in R by using vectorization is usually one of the best ways to improve performance. Since we can't replicate your data (e.g., tslength is not given), instead I'll generate a couple of functions to extract the estimated beta from randomly generated data. The replicate() function

Re: [R] Displaying Counts of Unused Factors in Contingency Tables with table()

2010-07-29 Thread Dennis Murphy
Hi, table() is behaving as documented with respect to your example. local.labels is a *character* vector with two distinct values and local.preds is a *character* variable with one distinct value. If you were expecting your table to divine that you wanted to include 'ah~' as a missing value in

Re: [R] Multiple binomial tests on a large table

2010-07-29 Thread Dennis Murphy
Hi: Here's one approach (not unique), and dragged out a bit to illustrate its different components. 1. Create a list object, something like l - vector('list', 600) 2. Populate it. There are several ways to do this, but one is to initially create a vector of file names and then populate the

Re: [R] Multiple binomial tests on a large table

2010-07-29 Thread Dennis Murphy
Hi: As it turns out, this is pretty straightforward using plyr's ldply() function. Here's a toy example: d1 - structure(list(X = c(11L, 9L, 13L, 13L, 18L), N = c(19L, 26L, 21L, 27L, 30L)), .Names = c(X, N), class = data.frame, row.names = c(NA, -5L)) w - sample(1:50, 5) d2 - data.frame(X =

Re: [R] where did the column names go to?

2010-07-29 Thread Dennis Murphy
Hi: On Thu, Jul 29, 2010 at 3:28 AM, pdb ph...@philbrierley.com wrote: I've just tried to merge 2 data sets thinking they would only keep the common columns, but noticed the column count was not adding up. I've then replicated a simple example and got the same thing happening. q1. why

Re: [R] how to 'stack' data frames?

2010-07-29 Thread Dennis Murphy
Hi: Here's a *reproducible* example: a - data.frame(w = rnorm(10), x = rnorm(10), y = rnorm(10), z = rnorm(10)) b - data.frame(w = rnorm(20), x = rnorm(20), x2 = rnorm(20), x3 = rnorm(20)) commonCols - intersect(names(a), names(b)) commonCols [1] w x rbind(a[commonCols], b[commonCols])

Re: [R] newton.method

2010-07-29 Thread Dennis Murphy
Hi: Interesting. Try the following; f is copied and pasted directly from your e-mail: f - function(x) 2.5*exp(-0.5*(2*0.045 - x)) + 2.5*exp(-0.045) + 2.5*exp(-1.5*x) - 100 curve(f, -3, 8) # plot it in a localized region abline(0, 0, lty = 2) There are two places where the function

Re: [R] xyplot with all columns of a data.frame on a single plot

2010-07-27 Thread Dennis Murphy
Hi: Another approach might be to use the melt() function in package reshape before creating the plot with xyplot, something along the lines of the following: library(reshape) mdat - melt(data, id = 'X') This should create a data frame with three columns: X, variable (all the D* names as factor

Re: [R] how to generate a random data from a empirical distribition

2010-07-27 Thread Dennis Murphy
Hi: On Mon, Jul 26, 2010 at 11:36 AM, xin wei xin...@stat.psu.edu wrote: hi, this is more a statistical question than a R question. but I do want to know how to implement this in R. I have 10,000 data points. Is there any way to generate a empirical probablity distribution from it (the

Re: [R] anderson-darling test

2010-07-27 Thread Dennis Murphy
Hi: I tried the following: library(sos) findFn('Anderson-Darling') found 49 matches; retrieving 3 pages 2 3 It appears that packages nortest and ADGofTest might be good places to start, but you can check out the others for yourself. HTH, Dennis On Tue, Jul 27, 2010 at 6:08 PM, Roslina

Re: [R] how to calculate the product of every two elements in two vectors

2010-07-24 Thread Dennis Murphy
as.vector(t(outer(A, B))) [1] 9 10 11 12 18 20 22 24 27 30 33 36 HTH, Dennis On Fri, Jul 23, 2010 at 8:11 AM, aegea gche...@gmail.com wrote: Thanks in advance! A=c(1, 2,3) B=c (9, 10, 11, 12) I want to get C=c(1*9, 1*10, 1*11, 1*12, ., 3*9, 3*10, 3*11, 3*12)? C is still a vector

Re: [R] legend in R plot

2010-07-22 Thread Dennis Murphy
Hi: It would really help to have a reproducible example to see exactly what problems you're having, but here's a simple manufactured example to illustrate how to produce a basic legend. The plot below is one with three different 'y' variables against the same x. The x and y limits are made wide

Re: [R] best way to apply a list of functions to a dataset ?

2010-07-21 Thread Dennis Murphy
that don't return numerics). Glen On Tue, Jul 20, 2010 at 6:55 PM, Dennis Murphy djmu...@gmail.com wrote: Hi: This might be a little easier (?): library(datasets) skewness - function(x) mean(scale(x)^3) mean.gt.med - function(x) mean(x)median(x) # -- # construct the function

Re: [R] lm: order of dropped columns

2010-07-21 Thread Dennis Murphy
Hi: (1) lm() drops columns in a rank-deficient model matrix X to make X'X nonsingular - this is called a full-rank reparameterization of the linear model. (2) How many columns of X are dropped depends on its rank, which in turn depends on the number of constraints in the model matrix. This is

Re: [R] Help me with prediction in linear model

2010-07-21 Thread Dennis Murphy
Hi: On Wed, Jul 21, 2010 at 8:46 AM, vijaysheegi vijay.she...@gmail.com wrote: Hi R-community, I have the code as follows,i Fitted model as follows lbeer-log(beer_monthly) t-seq(1956,1995.2,length=length(beer_monthly)) #beer_monthly contains 400+ entries This is unnecessary: t2=t^2

Re: [R] Variance of the prediction in the linear regression model (Theory and programming)

2010-07-21 Thread Dennis Murphy
Hi: On Wed, Jul 21, 2010 at 2:29 PM, Yi liuyi.fe...@gmail.com wrote: Hi, folks, Here are the codes: ## y=1:10 x=c(1:9,1) lin=lm(log(y)~x) ### log(y) is following Normal distribution x=5:14 prediction=predict(lin,newdata=x) ##prediction=predict(lin) ###

Re: [R] best way to apply a list of functions to a dataset ?

2010-07-20 Thread Dennis Murphy
Hi: This might be a little easier (?): library(datasets) skewness - function(x) mean(scale(x)^3) mean.gt.med - function(x) mean(x)median(x) # -- # construct the function to apply to each variable in the data frame f - function(x) c(mean = mean(x), sd = sd(x), skewness = skewness(x),

Re: [R] Correct statistical inference for linear regression models without intercept in R

2010-07-20 Thread Dennis Murphy
Hi: On Tue, Jul 20, 2010 at 2:41 AM, StatWM wmus...@gmx.de wrote: Dear R community, is there a way to get correct t- and p-values and R squared for linear regression models specified without an intercept? example model: summary(lm(y ~ 0 + x)) This gives too low p-values and too high R

Re: [R] Calculation of Covariance Matrix Calculation

2010-07-19 Thread Dennis Murphy
Hi: a - matrix(1:8, 2, 4) cov(a)# using cov() from stats package [,1] [,2] [,3] [,4] [1,] 0.5 0.5 0.5 0.5 [2,] 0.5 0.5 0.5 0.5 [3,] 0.5 0.5 0.5 0.5 [4,] 0.5 0.5 0.5 0.5 After using package sos to discover that ccov() is a function in package robust (which was

Re: [R] Reshaping data

2010-07-19 Thread Dennis Murphy
Hi: Here's one solution using function reshape() in the stats package (adapted from an R-help solution by Thomas Lumley on Nov. 26, 2002): d - read.table(textConnection( + ID begin_t1end_t1 begin_t2 end_t2 + Thomas 11/03/0413/05/06

Re: [R] problems with plot()

2010-07-19 Thread Dennis Murphy
Hi: As Duncan noted, your approach is at best inefficient. Consider the following example: # Generate some fake data: x - data.frame(x = rpois(10, 5), y = rnorm(10)) # Generate a list where each component is a row of x l - split(x, rownames(x)) # verify it's a list l # class of each list

Re: [R] Sequence from 2 Vectors

2010-07-19 Thread Dennis Murphy
Hi: Josh's solution is much simpler (and more practical, no doubt) than the one below, but I wanted to experiment with creating sequences using a vector of start indices and a corresponding vector of end indices: b - 1:3 # vector of start indices e - 3:5 # vector of end indices The

Re: [R] simple loop(?) analysing subsets

2010-07-18 Thread Dennis Murphy
Hi: Time to jack up your level of R knowledge, courtesy of the apply family. The 'R way' to do what you want is to split the data by species into list components, run lm() on each component and save the resulting lm objects in a list. The next trick is to figure out how to extract what you want,

Re: [R] multivariate graphs, averaging on some vars

2010-07-17 Thread Dennis Murphy
Hi: On Fri, Jul 16, 2010 at 3:44 PM, skan juanp...@gmail.com wrote: Hello I have a table of this kind: functionx1 x2 x3 2.232 1 1 1.00 2.242 1 1 1.01 2.732 1 1 1.02 2.770 1 2 1.00

Re: [R] plot month and year

2010-07-17 Thread Dennis Murphy
Hi: I'm a little more familiar with ggplot2 than zoo for graphing multivariate time series, so my response is based on that bias. On Sat, Jul 17, 2010 at 11:41 AM, linda.s samrobertsm...@gmail.com wrote: i am a beginner and tried to provide a reproducible example. is the following style a

Re: [R] slplot issue

2010-07-17 Thread Dennis Murphy
In which package would one find slplot? It's not in any of the 1800+ packages on my system... Dennis On Sat, Jul 17, 2010 at 1:28 PM, Shawn Way s...@meco.com wrote: In a prior life I was able to use slplot can change the xlim and ylim such that the ellipse was a perfect circle. It seems that

Re: [R] Creating Enumerated Variables

2010-07-16 Thread Dennis Murphy
Hi: Hadley's solution is certainly preferred here due to its relative simplicity. I just wanted to correct an error from my earlier post. On Thu, Jul 15, 2010 at 2:08 PM, Dennis Murphy djmu...@gmail.com wrote: Hi: I sincerely hope there's an easier way, but one method to get

Re: [R] threshold in plot

2010-07-16 Thread Dennis Murphy
Hi: Here's a simple example (divide through by 10 for your case): x - 1:10 y - rnorm(10, x, s = 0.3) clr - ifelse(x = 5, 'red', 'blue') plot(x, y, col = clr) HTH, Dennis On Fri, Jul 16, 2010 at 6:08 AM, azam jaafari azamjaaf...@yahoo.com wrote: Hi I want to draw a plot from observed and

Re: [R] how to collapse categories or re-categorize variables?

2010-07-16 Thread Dennis Murphy
Hi: See ? levels. Here's a toy example: x - factor(sample(0:2, 10, replace = TRUE)) x [1] 1 2 1 0 2 2 2 2 2 1 Levels: 0 1 2 levels(x) - c(0, 1, 1)# Change level 2 to 1 x [1] 1 1 1 0 1 1 1 1 1 1 Levels: 0 1 HTH, Dennis On Fri, Jul 16, 2010 at 10:18 AM, CC turtysm...@gmail.com wrote:

Re: [R] invalid factor level, NAs generated

2010-07-16 Thread Dennis Murphy
Hi Jared: Is it possible you're using read.table with variable names in line 1 but not using header = TRUE as an argument? HTH, Dennis On Fri, Jul 16, 2010 at 12:41 PM, Erik Iverson er...@ccbr.umn.edu wrote: snip I think I have identified the problem such that when I identify the

Re: [R] Nested if help

2010-07-16 Thread Dennis Murphy
Hi: I'm guessing that your time variable is not defined with a class that respects (time) ordering, so your first if statement is meaningless. In the absence of further information, either create a meaningful time/date variable or at the very least, an ordered factor. Given what you've provided,

Re: [R] Summing over intervals

2010-07-15 Thread Dennis Murphy
Hi: Tal was on the right track, but the function in package zoo that applies here is rollapply(): library(zoo) m-matrix(seq(1,80),ncol=20, nrow=4) t(apply(m, 1, function(x) rollapply(zoo(x), width = 5, FUN = mean, by = 5))) [,1] [,2] [,3] [,4] [1,]9 29 49 69 [2,] 10 30 50

Re: [R] Creating Enumerated Variables

2010-07-15 Thread Dennis Murphy
Hi: I sincerely hope there's an easier way, but one method to get this is as follows, with d as the data frame name of your test data: d - d[order(with(d, Age, School, rev(Grade))), ] d$Count - do.call(c, mapply(seq, 1, as.vector(t(with(d, table(Age, School)) d d ID Age School Grade

Re: [R] Storing processed results back into original objects

2010-07-15 Thread Dennis Murphy
Hi: This seems to work: b - lapply(Dlist, function(x) x[, columns]) dnames - c('D1', 'D2') for(i in seq_along(dnames)) assign(dnames[i], b[[i]]) HTH, Dennis On Thu, Jul 15, 2010 at 6:18 PM, Steven Kang stochastick...@gmail.comwrote: Hi all, There are matrices with same column names but

Re: [R] aggregate(...) with multiple functions

2010-07-15 Thread Dennis Murphy
Hi: A nice package for doing this sort of thing is doBy. Let's manufacture an example since you didn't provide one: set.seed(126) d - data.frame(g = rep(letters[1:3], each = 10), x1 = rnorm(30), x2 = rnorm(30, mean = 5), x3 = rnorm(30, mean =

Re: [R] Adding two files into one and vlookup

2010-07-08 Thread Dennis Murphy
Hi: merge(file2, file1, by = 'Date') DatePrice.x Price.y 1 03/07/2010 5.312006 56.92826 2 04/07/2010 673.070592 39.27409 3 05/07/2010 442.467939 42.59834 4 06/07/2010 851.915899 70.68512 5 07/07/2010 581.859242 10.92505 HTH, Dennis On Wed, Jul 7, 2010 at 8:07 AM, Raghu

Re: [R] Help With ANOVA (corrected please ignore last email)

2010-07-07 Thread Dennis Murphy
Hi: I'd suggest looking at the following plot (data in original post, copied below): library(lattice) stripplot(Intensity ~ Group, data = zzzanova) Some things stand out in this plot that merit attention. As Josh Wiley pointed out in an earlier reply, the concentration of -4.60517 values in

Re: [R] Help in the legend()

2010-07-06 Thread Dennis Murphy
Hi: You didn't specify what you meant in your original post by following that I had used didn't gave desired result (sic). I noted two potential problems: (i) the n in the plot is not what you expected it to be, and (ii) the legend didn't render in the range of values established by the graph you

Re: [R] Assign Formulas to Arrays or Matrices?

2010-07-06 Thread Dennis Murphy
Hi: See inline... On Tue, Jul 6, 2010 at 12:13 AM, McLovin dave_dec...@hotmail.com wrote: Hi, I am very new to R. I am hoping to create formulas and assign them to locations within an array (or matrix, if it will work). Here's a simplified example of what I'm trying to do: form.arr -

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