Hi all, I installed all required packages for plm, but pdata.frame is not a recognized function on R to start with. I followed the first page of "introduction to plm" by Croissant&Millo, Here are the messages: *> library(plm)Loading required package: kinship Loading required package: survival Loading required package: splines Loading required package: nlme Loading required package: lattice> library(Ecdat) > data(Produc) > pdata.frame(Produc,"state","year","pprod")Error: could not find function "pdata.frame"* I've tried the same codes on both PC and MAC with R 2.6.2. Neither of the systems worked. Please help. Thanks. Edward [[alternative HTML version deleted]]