On Oct 7, 2011, at 11:25 AM, Ana wrote:
Thanks! It helps. I completely forgot about the colnames function I added a "which(colnames(m)==n)" to my own function and now I can access with no problem the column by the number instead of the name.
'which' returns a logical vector. You could have also used the grep expression with value=F (the default) since the '[ , ]' operation can also use numeric arguments. The fundamental error was in trying to use the "$" operator.
-- David.
On Fri, Oct 7, 2011 at 5:09 PM, R. Michael Weylandt <michael.weyla...@gmail.com> <michael.weyla...@gmail.com> wrote:Perhaps something like this: Test <- function(m){ m <- if(is.character(m)) get(m) else m stopifnot(length(colnames(m))>0) n = colnames(m) # Process n however 2* m[, n] } That make sense? Hope it helps, Michael On Oct 7, 2011, at 11:03 AM, Ana <rrast...@gmail.com> wrote:How can I call matrix$col, inside a function? The matrix name is one of the variables of the function, while the column name I get by assuming that it should have a certain characters. something like this function(matrix){ colname=as.name(grep("[A-T a-t]ting",colnames(matrix),value=TRUE)) output=2*(matrix$colname) return(output) } The name of the column is Testing. ______________________________________________ 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.
David Winsemius, MD West Hartford, CT ______________________________________________ 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.
