similar to: Recommended Packages

I am introducing the scan() function to my class. Consider the following file (Scanexamp.Rnw ) \documentclass[12pt]{article} \begin{document} <<>>= height = scan() 64 62 66 65 62 69 72 72 70 part = scan(what = character(0)) "Soprano" "Soprano" "Soprano" "Alto" "Alto" "Tenor" "Tenor" "Bass"

I found myself wanting to average a vector [vec] within each level of a factor [Fac], returning a vector of the same length as vec. After a while I realised that lm1 <- lm(vec ~ Fac) fitted(lm1) did what I want. But there must be another way to do this, and it would be good to be able to apply other functions than mean() in this way. Cheers, Murray -- Dr Murray Jorgensen

I am exploring the result of clustering a large multivariate data set into a number of groups, represented, say, by a factor G. I wrote a function to see how categorical variables vary between groups: > ddisp <- function(dvar) { + csqt <- chisq.test(G,dvar) + print(csqt$statistic) + print(csqt$observed) + print(round(csqt$expected)) + round(csqt$residuals) + } > > x

I'm going to try my hand at converting some Fortran programs to R. Does anyone know of any good articles giving hints at such tasks? I will post a selective summary of my gleanings. Cheers, Murray -- Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html Department of Statistics, University of Waikato, Hamilton, New Zealand Email: maj at waikato.ac.nz

How do you stop R from putting up a dialog box when you quit Rgui? (I use Windows and I never save workspaces that way) Murray -- Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html Department of Statistics, University of Waikato, Hamilton, New Zealand Email: maj at waikato.ac.nz Fax 7 838 4155 Phone +64 7 838 4773 wk +64 7 849 6486 home

I can ask my question using and example from Chapter 1 of Pinheiro & Bates. > # 1.4 An Analysis of Covariance Model > > OrthoFem <- Orthodont[ Orthodont$Sex == "Female", ] > fm1OrthF <- + lme( distance ~ age, data = OrthoFem, random = ~ 1 | Subject ) > summary( fm1OrthF ) Linear mixed-effects model fit by REML Data: OrthoFem AIC BIC

I want to interlace two vectors. This I can do: > x <- 1:4 > z <- x+0.5 > as.vector(t(cbind(x,z))) [1] 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 but this seems rather inelegant. Any suggestions? Murray -- Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html Department of Statistics, University of Waikato, Hamilton, New Zealand Email: maj at waikato.ac.nz

Greetings all. Any help with the following would be appreciated. I want to create a data frame for each file in a directory. The following code does not work but it may show what I am trying to do: carmakes <- c('BMW','Chrysler','Citroen','Fiat','Ford','Holden','Honda',

I got a shock a few days ago when I accidentally visited www.r-project.com . I thought that the r-project site had been hacked until I realised my mistake. There is also a site www.r-project.net. Both of these sites appear to be Japanese. Does anyone know anything about them? I suppose that it is not unusual for names close to those of popular sites to be used. It is good that they use a

I have just installed R 2.11.1 on my XP laptop. I like html help for browsing but text help for on-the-fly look-ups. I was a bit surprised when I was asked to choose between them during the installation. I chose text, thinking I could fix the html help later, which is what I am trying to do now. Now when I ask for html help my browser goes to 'http://-ip-number-/doc/html/index.html'

I'm running R 1.2.2 under windows 98 on a Pentium 133 laptop. I can't seem to retrieve the package MASS data sets: > library(MASS) > data(wtloss) Warning message: Data set `wtloss' not found in: data(wtloss) > data(abbey) Warning message: Data set `abbey' not found in: data(abbey) And yet all the .rda files for the MASS datasets are in D:\Program

If I want to display a few polynomial regression fits I can do something like for (i in 1:6) { mod <- lm(y ~ poly(x,i)) print(summary(mod)) } Suppose that I don't want to over-write the fitted model objects, though. How do I create a list of blank fitted model objects for later use in a loop? Murray Jorgensen -- Dr Murray Jorgensen

Hi all, I have just found out that the machine learning group in our Faculty has a lot of spare capacity on their FreeNX servers. I do not know a lot about these beasts but I understand that they are a free version of something produced by a firm called "NoMachine". They are designed for executing parallel algorithms and I thought that they might be of use in a project of mine

I would like a function to strip quotes off character strings. I should work like this: > A <- matrix(1:6, nrow = 2, ncol=3) > AF <- as.data.frame(A) > names(AF) <- c("First","Second","Third") > AF First Second Third 1 1 3 5 2 2 4 6 > names(AF)[2] [1] "Second" > attach(AF) >

Well I don't know if anyone can help with this but it will be interesting to know if others have had the same problem. I can't start R at home on my laptop [ I'm using 1.8.1 under Windows XP]. When I click on the shortcut I get the usual Windows box for when an application needs to close. A couple of clicks down it displays the following: Error signature AppName: rgui.exe

The birth weight example from ?stepAIC in package MASS runs well as indeed it should. However when I change stepAIC() calls to step() calls I get warning messages that I don't understand, although the output is similar. Warning messages: 1: In model.response(m, "numeric") : using type="numeric" with a factor response will be ignored (and three more the same.) Checked

Has anyone got a cute way of compiling a table of the available plotting symbols? I've been repeatedly pasting in cno <- cno + 1 cno plot(x,y,pch=cno) which is tedious, and besides I have to note down the symbols by hand. Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html Department of Statistics, University of Waikato, Hamilton, New Zealand Email: maj at

[Using R 2.2.0 on Windows XP; OK, OK, I will update soon!] I have noticed some undesirable behaviour when applying ifelse to a data frame. Here is my code: A <- scan() 1.000000 0.000000 0.000000 0 0.00000 0.027702 0.972045 0.000253 0 0.00000 A <- matrix(A,nrow=2,ncol=5,byrow=T) A == 0 ifelse(A==0,0,-A*log(A)) A <- as.data.frame(A) ifelse(A==0,0,-A*log(A)) and this is the output:

Consider the following: > A <- 1:10 > A [1] 1 2 3 4 5 6 7 8 9 10 > dim(A) NULL > dim(A) <- c(2,5) > A [,1] [,2] [,3] [,4] [,5] [1,] 1 3 5 7 9 [2,] 2 4 6 8 10 > dim(A) [1] 2 5 > dim(A) <- 10 > A [1] 1 2 3 4 5 6 7 8 9 10 > dim(A) [1] 10 Would it not make sense to have dim(A) = length(A) for all vectors?

G'day list! I'm thinking about programming likelihood and score intervals for generalized linear models in R based on the paper "On the computation of likelihood ratio and score test based confidence intervals in generalized linear models" by Juha Alho (1992) (Statistics in Medicine, 11, 923-930). Being lazy, I thought that I would ask if anyone else on the list has