> Why does R need the concept of "Vector"? In my opinion, it is a useless and > confusing concept. A vector is simply a special case of a matrix whose row > or column number is equal to 1. When I take submatrix from one matrix and > if row or column number is 1, R will automatically convert it into a vector. > It is very straightforward that a submatrix of a matrix should be a matrix. > In each time, I have to use as.matrix() to convert the vector back to > matrix. It is very annoying!
Good thing there's a way to get around this then: R> m <- matrix(1:20, 4, 5) R> m [,1] [,2] [,3] [,4] [,5] [1,] 1 5 9 13 17 [2,] 2 6 10 14 18 [3,] 3 7 11 15 19 [4,] 4 8 12 16 20 R> m[,1] [1] 1 2 3 4 R> m[,1,drop=FALSE] [,1] [1,] 1 [2,] 2 [3,] 3 [4,] 4 R> is.matrix(m[,1,drop=FALSE]) [1] TRUE -steve -- Steve Lianoglou Graduate Student: Computational Systems Biology | Memorial Sloan-Kettering Cancer Center | Weill Medical College of Cornell University Contact Info: http://cbio.mskcc.org/~lianos/contact ______________________________________________ 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.