Try this: aggregate(list(Number=x$Number), by=list(Gene_Name=x$Gene_Name), sum)
On 25/03/2008, Charles Murtaugh <[EMAIL PROTECTED]> wrote: > Hi-- > > This is a question with a trivial and obvious answer, I'm sure, but I can't > seem to find it in the help files and books that I have handy. I have a > dataframe consisting of two columns, "Gene_Name," a list of gene symbols, and > "Number," a numeric measure of how frequently a tag representing that gene > showed up in a SAGE library. Several of the genes are represented by > multiple tags, and therefore are present more than once in the list, e.g.: > > 1167 Zcchc8 6 > 1168 Zcwpw1 5 > 1169 Zdhhc18 6 > 1170 Zdhhc20 5 > 1171 Zdhhc3 6 > 1172 Zdhhc3 5 > 1173 Zeb2 9 > 1174 Zeb2 6 > > What I want is to collapse the list by gene name, such that duplicates are > summed up and appear only once in the final version: > > > > Zcchc8 6 > > Zcwpw1 5 > > Zdhhc18 6 > Zdhhc20 5 > > Zdhhc3 11 > > Zeb2 15 > > > > The only way I can figure out to do this is via rowsum: > > > > > rowsum (Number,Gene_Name) > > > > gives me exactly what I want, *except* that in the end, I am left with a > matrix containing the Number values and with the Gene_Names used as row names > (the output therefore looks exactly as printed above) -- what I want is a > dataframe equivalent to the starting table, with numbered rows and separate, > accessible columns containing the Gene_Name and Number values. > > > > I was able to put such a dataframe together manually, by cobbling together > the row names of the above list with the values: > > > > > genes.unique <- data.frame (rownames (rowsum(Number,Gene_Name)), > rowsum(Number,Gene_Name)) > > > > but then I have to manually replace the row names of the dataframe with > numbers, to get back to what I wanted in the first place. > > > > I hope this makes some sort of sense. Is there an easier way to do this? > Thanks in advance! > > > > Charlie Murtaugh > > > > > > > > ===== > > L. Charles Murtaugh > Assistant Professor > > University of Utah > Dept. of Human Genetics > 15 N. 2030 E. Rm. 2100 > Salt Lake City, UT 84112 > > tel 801-581-5958 > fax 801-581-6463 > email [EMAIL PROTECTED] > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.
