similar to: memory efficiency in R

There was some interest in the commands for creating an HTML file of 3D graphics that can be shown with a Java applet. Looking at things I discovered (of course) that I should really clean up quite a few things before releasing it for real. I hope to do some of that this weekend. In the meanwhile, here are a couple of pointers to the Java applet & documentation (apparently free for

I am trying to find a way to analyze a "simple" mixed model with two levels of a treatment, a random blocking factor, and (wait for it) negative binomial count distributions as the response variable. As far as I can tell, the currently available R offerings (glmmGibbs, glmmPQL in MASS, and Jim Lindsey's glmm code) aren't quite up to this. From what I have read (e.g.

Does the nls package actually allow for weighted nonlinear regression? (i.e., I have data with individual variances associated, I'd like to use 1/var to weight the points.) The "nls" function does have a weights argument, but it doesn't seem to do anything as far as I can tell ... thanks ... Ben Bolker -- 318 Carr Hall bolker at

This is off-topic (apologies), but I thought I might get a lead or two here. I'm interested in generating random deviates from a multivariate distribution which is a generalization of the beta distribution -- the Bayesian canonical distribution for the parameter estimates of a multinomial distribution. Given a vector (length n-1) of probabilities p and a vector (length n) of shape

I'm probably missing something very basic here, but: I've written some C code that I load into R dynamically. In the course of this C code, I generate some multinomial random deviates. I initially used the publically available "randlib" library, which also implements its own random number generator and binomial deviates (which are used to generate the multinomial deviates).

Just a quick question, in case I'm doing something really boneheaded that could be easily sorted out. I'm attempting to save() datasets on Linux (R 1.1.1) and load() them on Win2K (rw1011, fetched from CRAN today). I get the "restore file corrupted" message every time. I've tried saving with ascii=TRUE and FALSE, and the ASCII versions look OK (it's my impression

I'm having problems (or to be precise a student is having problems, which I'm having problems helping her with) trying to use glm.nb() from the MASS package to do some negative binomial fits on a data set that is, admittedly, wildly overdispersed (some zeros and some numbers in the hundreds). glm.nb is failing to converge, and furthermore is (to my surprise) producing values of theta

I want to add my two cents of congratulation to the R core team. I also want to encourage everyone who uses R to be an active, not a passive user -- the fastest way R will get better is if the folks who use it submit bug reports, suggestions, R code for their particular fields, documentation, even patches and code fixes. R is big and complicated enough now that we can't leave testing to

Can we add a note to the documentation that setting par(fig) resets par(mfrow) and par(mfcol) to c(1,1)? Or are mfrow and mfcol now deprecated in favor of all the split screen stuff? (I was spending the morning trying to write some code that plotted multiple subplots within whatever plot region was active at the moment; I was able to set and reset fig successfully, but got very confused as to

There are a few inconsistencies, at least, in some of the functions that generate random deviates from particular distributions (I think they're bugs because they're inconvenient, but maybe someone can make an argument for the current behavior). If people think these are really bugs I can submit them, together or separately. 1. rlnorm(n,mean,sd) gives NaN for sd=0, rather than always

For various reasons, I've opted to make my packages available from my own web page rather than submitting them to CRAN (mostly laziness -- for a long time I didn't have the packages quite cleaned up enough to pass all the tests). It occurred to me to wonder about the scripts used by CRAN maintainers to generate the PACKAGES file, and to generate PACKAGES.html from PACKAGES. Are

Some students of mine are trying to use gnls, the generalized non-linear least squares function within the nlme library, to study evolutionary questions where correlations between traits at the species level are non-independent because of the evolutionary relatedness of the species. Specifically, they're using a non-linear function (log(sexual dimorphism) ~ log(a + b*variation in mating

When using test="F" in stat.anova() / anova.glm(), R uses the assumed dispersion parameter for the specified family (e.g. scale=1 for binomial), while S-PLUS automatically uses the estimated dispersion parameter (residual deviance/residual df). I think there are good reasons for the behavior in R -- it fits with the "you get what you actually asked for" philosophy -- and

Just thought people might be interested to know that the latest version of R-win now runs under Wine, the windows emulator for Linux (ver. 20001202). (I originally tried this a couple of releases back because a student seemed to be having system-specific problems and I was attempting to be lazy.) The recent switch from crtdll to msvcrt seems to have helped with Wine compatibility. I

Some of my students were interested in a plot where the sizes of the symbols were proportional to the number of repeats in the data (I have them plotting discrete data, so there are often overlaps). Here's the solution I came up with, which seems clever (to me) but not necessarily the best way. Can anyone suggest improvements? sizeplot <- function(x,y,maxsize=0.2,

In the optim() documentation, the control parameter "maxit" says "There is no other stopping criteria." That should be "are", or "criterion" ... While I'm at it -- poking at the code a little bit, it looks as if the initial simplex is set from the initial point by displacing each parameter value by max(0.1,0.1*pmax(fabs(Bvec))), where Bvec is the

I just sent a bug report about "mailx" being the default mailer, before I looked at bug.report() carefully and saw that it checked "/usr/ucb/mail", and "Mail" as well as "mailx". I guess I had had the problem with this in a previous version. Would it be clearer to have .Options$mailer be a vector or list of alternate mailers that were checked in turn,

I have found what seems to be a bug in warning(), but perhaps I'm being really boneheaded (it's happened before). Essentially, warning() seems to segfault if its argument is greater than 8191 characters (8192 is defined as BUFSIZE in errors.c, so a quick workaround would be to boost this ...) The bug was initially provoked by trying to concatenate two long tables -- the warning message

The besselK() function knows about overflows/underflows internally; there is a constant xmax_BESS_K in src/nmath/bessel.h (and referred to only in bessel_k.c), equal to 705.342, which is checked if expon.scaled is FALSE. (The equivalent number for bessel_i.c is 709, defined as exparg_BESS in bessel.h.) However, besselK(x) silently returns +Inf if x>705.342. This behavior is reasonable for

How difficult would it be (I could try myself if someone thought it would be straightforward) to change read.table to allow a comment character such as # or %? My thought would be that anything on a line following a comment character would be ignored (so that the combination of blank.lines.skip=TRUE and a comment at the beginning of the line would lead to a line being skipped completely).