Hi, I have a question about using lm on matrix, have to admit it is very trivial but I just couldn't find the answer after searched the mailing list and other online tutorial. It would be great if you could help.
I have a matrix "trainx" of 492(rows) by 220(columns) that is my x, and trainy is 492 by 1. Also, I have the newdata testx which is 240 (rows) by 220 (columns). Here is what I got: py <- predict(lm(trainy ~ trainx ), data.frame(testx)) Warning message: 'newdata' had 240 rows but variable(s) found have 492 rows The fitting formula I intended is: trainy ~ trainx[,1] + trainx[,2] + .. +trainx[,220]. Any help, please? Best, Baoqiang ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
