similar to: Defining own variance function / quasi-likelihood in a GLM

Hello, I've had a quick look on the list and can't find an answer to this niggle. Whilst debugging some code, I noticed that looping variables in R are not local to the loop as seams common in procedural languages. For example consider the following piece of code: for(i in 1:3){ cat(i,"") for(i in c("a","b","c")){ cat(i,"")

Hello, I have found a problem with using the glm function with a gamma family. I have a vector of data, assumed to be generated by a gamma distribution. The parameters of this gamma distribution are estimated in two ways (i) using the glm() function, (ii) "by hand", using the optim() function. I find that the -2*likelihood at the maximum found by (i) is substantially larger than that

Hello folks, Any ideas how to do this? data.frame is a data frame with column names "x1",...,"xn" y is a response variable of length dim(data.frame)[1] I want to write a function function(y, data.frame){ lm(y~x1+...+xn) } This would be easy if n was always the same. If n is arbitrary how could I feed the x1+...+xn terms into lm(response~terms)? Thanks Richard -- Dr.

Hi Just one of those niggles....... I've just been trying to plot a filled circle. I thought that this would do it plot(1,1,type="n") points(1,1,pch=1,bg="blue",cex=5) #bg: background ("fill") color for open plot symbols But I need to do this instead points(1.2,1,pch=19,col="blue",cex=5) Am I misunderstanding the "bg" option in the points

When reading comma-delimited files as saved from a spreadsheet (unfortunately many of my scientific collaborators give me these) in read.table(), missing values are spotted most of the time. Unfortunately when comma is the first character on the line it gets it wrong. For example, reading the file 1,,3 ,5,6 ,8,9 with read.table("test.dat", header=F, sep=",") R gives

Has anyone tried to build R on Suns by linking to the versions of BLAS and LINPACK in the Sun Performance Library rather than the standard versions included in the distribution? On the face of it this would seem to be a highly desirable thing to do since these versions of the routines are more efficient and can exploit parallelism on multiprocessor machines. David Clayton MRC Biostatistics

Hello, Has anyone written up code to estimate for example a simple logit using quasi-likelihood? I know that glm() already does this, but I'd like to do some tinkering with the variance function beyond what glm() allows. I've scanned online sources and everyone seems to use glm(). Will take a crack at it if necessary but have zero experience w/q-likelihood and not that much with

Is there any way of running R in ESS using -n and -v arguments other than the default? Thanks Jonathan -- Dr. Jonathan Myles e-mail:jonathan.myles at mrc-bsu.cam.ac.uk MRC Biostatistics Unit Tel. 01223 330371 Institute of Public Health FAX 01223 330388 University Forvie Site Robinson Way CAMBRIDGE CB2 2SR

In a glm() call using a quasi() family, one may define a custom variance function in the form of a "list containing components varfun, validmu, dev.resids, initialize and name" (quoting the help page for family). In trying to do so, I run into the following issue that I have not seen discussed previously: x <- runif(1000, min=0, max=1) y <- x + rnorm(1000, mean=0, sd=1)*x^(3/4)

Hi all, Cameron and Trivedi in their 1998 Regression Analysis of Count Data refer to NB1 and NB2 NB1 is the negative binomial model with variance = mu + (alpha * mu^1) yielding (1+alpha)*mu NB2 sets the power to 2; hence, variance = mu + (alpha*mu^2) I think that NB2 can be requested via negbin2<-glm(hhm~sex+age,family=quasi(var="mu^2",link="log")) Is

Is there a way to "unplug" the windows graphics from R, so that it will work across a teletype telnet session or in a Linux box proving resistant to having windows added to it? Thanks Jonathan Myles -- Dr. Jonathan Myles e-mail:jonathan.myles at mrc-bsu.cam.ac.uk MRC Biostatistics Unit Tel. 01223 330371 Institute of Public Health FAX 01223 330388 University Forvie

Changing from 0.64.1 to 0.64.2 is causing some dynamically-loaded code to crash with the message: ld.so.1: /usr/local/lib/R/bin/R.binary: fatal: relocation error: file /homef/jonm/glib/ggg/libs/glmm.so: symbol R_chk_calloc: referenced symbol not found (I've added carriage returns) what am I doing wrong? Jonathan -- Dr. Jonathan Myles e-mail:jonathan.myles at mrc-bsu.cam.ac.uk

Thanks to everyone who helped with my query---Professors Riply, Bates, Lumley, and Tim Keitt. I said <snip> > My worries are > > a) That I've used calloc rather than S_alloc throughout. Professors Bates and Ripley both pointed out that calloc should be replaced by Calloc and free by Free, which, I'll do. ---- I said: > b) That I've used the following

Is there a platform-independent way of checking in R whether a given file exists in the user's filespace? (so in a unix system, can you check within R whather, say, /homef/jonm/thisfile exists) Thanks Jonathan Myles -- Dr. Jonathan Myles e-mail:jonathan.myles at mrc-bsu.cam.ac.uk MRC Biostatistics Unit Tel. 01223 330372 Institute of Public Health FAX 01223 330388

Is there any way of getting just the LaTex output which R CMD Rd2dvi generates on the way to produces a .dvi file, which could then be incoorporated into another document? Thanks, Jonathan -- Dr. Jonathan Myles e-mail:jonathan.myles at mrc-bsu.cam.ac.uk MRC Biostatistics Unit Tel. 01223 330372 Institute of Public Health FAX 01223 330388 University Forvie Site

Where are the archives of r-help kept, please? Jonathan -- Dr. Jonathan Myles e-mail:jonathan.myles at mrc-bsu.cam.ac.uk MRC Biostatistics Unit Tel. 01223 330371 Institute of Public Health FAX 01223 330388 University Forvie Site Robinson Way CAMBRIDGE CB2 2SR -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list --

I have C routines in a collection of files "/homef/jonm/postdocs/GLMM_project/Cprogs/nn/misc.o" "/homef/jonm/postdocs/GLMM_project/Cprogs/nn/random.o" "/homef/jonm/postdocs/GLMM_project/Cprogs/nn/ars.o" ... etc , where the third file includes functions which call functions in the second. In S, the function > gload function() {

Hello I'm fitting a gls model with a variance-covariance structure and an getting an error message I don't understand I'm using gls() from the nlme library with the structure defined by correlation = corSymm(form = ~1|Subject), weights = varIdent(form=~1|strata) I get the error Error in recalc.corSymm(object[[i]], conLin) : NA/NaN/Inf in foreign function call (arg 1) My

How might you fit a generalized linear model (glm) with variance = mu+theta*mu^2 (where mu = mean of the exponential family random variable and theta is a parameter to be estimated)? This appears in Table 2.7 of Fahrmeir and Tutz (2001) Multivariate Statisticial Modeling Based on Generalized Linear Models, 2nd ed. (Springer, p. 60), where they compare "log-linear model fits to

# Hello R Users, # # I would like to fit a glm model with quasi family and # logistical link function, but this does not seam to work # with binary data. # # Please don't suggest to use the quasibinomial family. This # works out, but when applied to the true data, the # variance function does not seams to be # appropriate. # # I couldn't see in the # theory why this does not work. # Is