Full_Name: Xiaoping Jin Version: 1.80 OS: window xp Submission from: (NULL) (24.223.234.248) I have downloaded R 1.80 recently. I found there was some problems, but I do not know the reason: 1. I can not do large interation in such new version. For example, for( i in 1:36535) { if(DAT$age[i]==4) DAT$year3[i]<-DAT$year[i] } it seemed to be stuck there, but it computes very quickly in the old version (such as R 1.40) 2. About RCMD SHLIB command, in such new version, if I use RCMD SHLIB to complie C program, it will complie all of C program in that directory, although I only specify one C program. For example, RCMD SHLIB weibul.c but I have dtheta.c in that directory, it will also compile dethea.c. This does not happen in the old R version. Hope you can tell me some reason. Thanks!