search for: rlevi

I'm interested in writing a function that constructs a new plot on the current graphics device if no plot exists there yet, but adds lines to the existing plot if a plot is already there. How can I do this? It seems to me that the exists() function might be co-opted to do this, but it's not obvious how. Many thanks, Roger -- Roger Levy Email: rlevy at ucsd.edu

I'm interested in doing multinomial logistic regression with equality constraints on some of the parameter values. For example, with categorical outcomes Y_1 (baseline), Y_2, and Y_3, and covariates X_1 and X_2, I might want to impose the equality constraint that \beta_{2,1} = \beta_{3,2} that is, that the effect of X_1 on the logit of Y_2 is the same as the effect of X_2 on the

Hi all, I use the excellent packages rjags and cacheSweave, and unfortunately seem to have found an incompatibility between them. Below are a minimal .Rnw file and corresponding JAGS model file which illustrate the problem: *** JAGS model file; name=j.bug *** model { mu ~ dnorm(0,1.0E-5) sigma ~ dunif(0,100) for(i in 1:length(y)) { y[i] ~ dnorm(mu,sigma) } } *** *** .Rnw

Hi, I'm trying to write a general-purpose "lexicon" class and associated methods for storing and accessing information about large numbers of specific words (e.g., their frequencies in different genres). Crucial to making such a class practically useful is to get hashing working correctly so that information about specific words can be accessed quickly. But I've never really

Hi, When using splom() in the lattice package, I would like to be able to access the row and column number of each individual pairs plot , similar to the way that current.row() and current.column() can be used in other lattice plotting functions such as xyplot. For example, I would like to be able to write something along the lines of library(mvtnorm) library(lattice) y <-

I'm writing a book using Sweave which includes Unicode characters which R's postscript and pdf graphics devices don't handle properly. The cairo graphics device does handle these characters properly. Thus I'd like to be able to instruct Sweave to use cairo (either sometimes or always) to produce graphics when it processes R code. Is this possible? Many thanks, Roger Levy --

While I have been able to install rjags on my Windows computer, oddly I have been unable to install rjags successfully on my 64-bit Linux compute server (etch, Linux kernel 2.6.18). I am required to specify the JAGS module directory upon installation; when doing this within R, I get:

I'm interested in a version of tapply() that operates with shingles instead of factors. For instance: x <- c(1,1,2,2,3,3) y <- c(1,1,1,0,0,0) s <- shingle(x,intervals=cbind(c(0.5,1.5),c(2.5,3.5))) # the following function should exist! tapply.shingle(x,s,mean) # returns the vector c(0.75,0.25) I've written such a function as follows: tapply.shingle <-

Hi Rob The stream format has nothing to do with your audio files. I probably have 70% MP3's and 30% Ogg Vorbis files, and 1 or 2 WAV files for jingles on my hard drive. I only encode new CD's to Ogg Vorbis. But my station is streaming in AAC+ format, and I have also streamed in Ogg Vorbis format simultaneously. There is no way I would bother streaming in MP3 format. It's 15+

I have a data frame with Cyrillic text that I would like to be able to view under RGui. Unfortunately I can't figure out from the manuals how to make this happen -- can someone point me in the right direction? Thanks, Roger Levy