Thank you all. Really! I have used the following function: apply(dfrm, 1, function(x) mean(x[x>=0]) )
Someone of you even gave me a few interesting explanations about why to use it. Still thank you all. Andrea On Mon, May 14, 2012 at 6:52 PM, David Winsemius <dwinsem...@comcast.net>wrote: > > On May 14, 2012, at 12:32 PM, Andrea Sica wrote: > > Dear all, >> >> I am sure it won't be difficult for you!! >> I need to calculate the average among variables for the single units of my >> dataset. >> But, while doing it, I need to do not consider some values. >> To better explain, think like there are two units and three variables: >> >> V1 V2 V3 >> [1] 3 -2 4 >> [2] -1 4 1 >> >> and you want to calculate the average by row, without considering those >> negative values: >> >> => mean(1row) = (3+4)/2 >> => mean(2row) = (4+1)/2 >> > > perhaps (untested in absence of reproducble example): > > apply(dfrm, 1, function(x) mean(x[x>=0]) ) # would also work for a matrix > object. > > >> Could anyone please give me the commands to do that in R? >> >> Thank you so much >> >> [[alternative HTML version deleted]] >> >> ______________________________**________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> >> PLEASE do read the posting guide http://www.R-project.org/** >> posting-guide.html <http://www.R-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > > David Winsemius, MD > West Hartford, CT > > [[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.