From: Jim Lindsey <jlindsey@luc.ac.be> Message-Id: <9605130724.AA16656@alpha.luc.ac.be> Subject: R-alpha: Bugs To: r-testers@stat.math.ethz.ch Date: Mon, 13 May 1996 09:24:11 +0200 (MET DST) I have been working with 0.4 over the weekend and found the following problems. I have just downloaded 0.5 but have not checked if they are corrected. I have been working primarily with glm() especially with binomial and poisson. (1) the workspace does not save options (it did in 0.1) such as contr.treatment (2) for a saturated model with glm(), I always obtain Warning: NAs produced in function "pt" Then in the table of coefficients, P(>|t|) is a column of NAs This does not happen for unsaturated models. (3) with contr.treatment, coefficients are labelled from 1 to k-1 as if the last category were baseline, but the estimates correspond to categories 2 to k with the first set to zero i.e. baseline (4) with saturated models, 10 iterations are always used with the Warning: Algorithml did not converge whereas GLIM stops after 2-3 cycles. Of course, after 10 iterations, the deviance is much closer to zero than in GLIM (5) For seemingly random combinations of data and covariate codings, binomial gives Error in if(abs((dev-devold)/sum(dev^2)) < control$epsilon & abs((coef -coefold)/sum( : missing value where logical needed. Here is an example: y1 <- c(23,35) y2 <- c(34,132) inf <- cbind(y1,y2) cont <- c(0,1) glm(inf~cont,family=binomial) however, if I define cont <- c(-1,1), it works! I also have more complex examples of this problem. Cheers, Jim =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- r-testers mailing list -- To (un)subscribe, send subscribe or unsubscribe (in the "body", not the subject !) To: r-testers-request@stat.math.ethz.ch =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-