[R] a problem with is.na

Hello, I have observed the following odd behavior of "is.na( )" and hope someone can give me an explanation Example: X1=rep(1:2,5)[-1] X2=rep(1:5,rep(2,5))[-1] y= runif(9) y[3]=NA xtabs(y~x1+x2) Now xtabs(is.na(y)~x1+x2) says that cell 2,2 is NA x2 x1 1 2 1 0 0 2 0 1 3 0 0 4 0 0 5

[R] Inverse Gaussian dist in a GEE model

For a simulation study, I need to fit a GEE with a IG distribution and using a log link function. As far as I know, there are two GEE packages available ('gee' and 'geepack') but none of them supports IG. I've also tried using family=quasi("log","mu^3") (without luck!).' Any guidance is highly a

[R] Simulating underdispersed counts

Hello, Anyone who knows a fast and accurate algorithm for generating draws from an underdispersed Poisson distribution. Or even better, if there is a package containing such an implementation. Thanks Rene __ R-help@r-project.org mailing list https:/

[R] environment and scoping

I haven't quite figured out how I can change the environment of a function. I have a main function and want to use different auxillary functions, which I supply as parameter (or names). What I want to do is something like this: main.fun=function(aux.fun,dat){ x <- 1 fun.dat() } aux.fun.one

[R] Error: (subscript) logical subscript too long

As part of a larger program I have a rather long and involved sub-procedure which fails to work, It manipulates some large matrices, stored to the disc. The procedure halts with the message: Error: (subscript) logical subscript too long Can anyone give advice about what may cause this error an