Gabor, David, thank you. David, your last suggestion is what I need.
Regards, Sergey On Mon, Sep 6, 2010 at 16:12, David Winsemius <dwinsem...@comcast.net> wrote: > > On Sep 6, 2010, at 9:56 AM, Sergey Goriatchev wrote: > >> Hello everyone. >> >> Say we have the following: >> >> a <- matrix(c(-75, 3, 5, 9, 2, 3, 5), nrow=1, dim=list("06092010", >> c("ES", "PT", "Z ", "CF", "GX", "ST", "EO"))) >> b <- matrix(c(-5, 2, 4, 12, 5), nrow=1, dim=list("06092010", c("PT", >> "CF", "AT", "EM", "ST"))) >> d <- cbind(a, b) >> >> I want to calculate sums of the columns that have similar column names >> and then output this summary >> What I want to have is an array that looks like: >> >> ES PT Z CF... >> -75 -2 5 11... >> >> I tried the following, but it did not work: >> aggregate(d, list(colnames(d)), sum) > > ES is not in the duplicated column names so perhaps your English > specification is not what you meant: >> d > ES PT Z CF GX ST EO PT CF AT EM ST > 06092010 -75 3 5 9 2 3 5 -5 2 4 12 5 > >> dupled <- colnames(d)[duplicated(colnames(d))] >> sapply(dupled, function(x) sum( d[, x])) > PT CF ST > 3 9 3 > > If you wanted simple a sum over unique column names then it would have been > somewhat simpler (no need to construct a duplicated set): > >> sapply(unique(colnames(d)), function(x) sum( d[, x])) > ES PT Z CF GX ST EO AT EM > -75 3 5 9 2 3 5 4 12 > >> >> How can I achieve my objective? >> >> Thank you in advance. >> >> Sergey >> >> ______________________________________________ >> 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 > > -- Kniven skärpes bara mot stenen. ______________________________________________ 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.