Define inner as in: http://tolstoy.newcastle.edu.au/R/e4/help/08/08/19562.html and use that with identical to define an inner product:
m <- matrix(c(1, 2, 1, 2, 3, 2), 2) # test matrix m colSums(inner(m, u <- unique(m,,2), identical)) u Please provide actual code to create test examples and expected results when you post. Read the last line to every message in r-help and the posting guide. On Sat, Nov 22, 2008 at 3:42 PM, Salas, Andria Kay <[EMAIL PROTECTED]> wrote: > I need help determining the unique columns of a matrix and the numbers of > each unique column. For example, let's say I have a matrix with 6 columns, 2 > of these are filled with the value of 1 and the other 4 are filled with the > value of 0. I would then like to have a command that tells me what the > unique columns are (so columns with 1s and columns with 0s) and the number of > each type of column (so 2 columns of 1s and 4 columns of 0s) that occur in > the matrix. > > Thank you for any help anyone can provide!! I have been very impressed with > the help that I have received so far!! Thank you! > ______________________________________________ > 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. > ______________________________________________ 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.
