Hi, See the code below.
'x' is a frame. x$C1 are all numbers 1, 2 and 3. 'as.matrix(x)' convert x$C1 to strings "1", "2" and "3". I'm wondering how to maintain that the first column of 'as.matrix(x)' still numbers. Regards, Peng $ cat read.csv "C1","C2" "1","x" "2","y" "3","z" $ Rscript read.csv.R > x=read.csv("read.csv") > str(x) 'data.frame': 3 obs. of 2 variables: $ C1: int 1 2 3 $ C2: Factor w/ 3 levels "x","y","z": 1 2 3 > as.matrix(x) C1 C2 [1,] "1" "x" [2,] "2" "y" [3,] "3" "z" > ______________________________________________ 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.