Hi Or maybe table
> mat<-matrix(sample(LETTERS[1:4], 200, replace=T),40,5) > df<-data.frame(mat) > table(df$X4) A B C D 8 12 11 9 > is what is wanted HTH Petr On 19 Aug 2005 at 7:24, Sean O'Riordain wrote: > Hi, > I'm not sure what you actually want from your email (following the > posting guide is a good way of helping you explain things to the rest > of us in a way we understand - it might even answer your question! > > I'm only a beginner at R so no doubt one of our expert colleagues will > help me... > > > fred <- data.frame() > > fred <- edit(fred) > > fred > A B C D E > 1 1 2 X Y 1 > 2 2 3 G L 1 > 3 3 1 G L 5 > > fred[,3] > [1] X G G > Levels: G X > > fred[fred[,3]=="G",] > A B C D E > 2 2 3 G L 1 > 3 3 1 G L 5 > > so at this point I can create a new dataframe with column 3 (C) == > "G"; either explicitly or implicitly... > > and if I want to calculate the sum() of column E, then I just say > something like... > > > sum(fred[fred[,3]=="G",][,5]) > [1] 6 > > > > now naturally being a bit clueless at manipulating stuff in R, I > didn't know how to do this before I started... and you guys only get > to see the lines that I typed in and got a "successful" result... > > according to section 6 of the "Introduction to R" manual which comes > with R, I could also have said > sum(fred[fred$C=="G",]$E) [1] 6 > > Hmmm.... I wonder would it be reasonable to put an example of this > type into section 2.7 of the "Introduction to R"? > > > cheers! > Sean > > > On 18/08/05, A. Mani <[EMAIL PROTECTED]> wrote: > > Hello, > > I want to avoid loops in the following situation. There is a > > 5-col > > dataframe with col headers alone. two of the columns are > > non-numeric. The problem is to calculate statistics(scores) for each > > element of one column. The functions depend on matching in the other > > non-numeric column. > > > > A B C E F > > 1 2 X Y 1 > > 2 3 G L 1 > > 3 1 G L 5 > > and so on ...30000+ entries. > > > > I need scores for col E entries which depend on conditional > > implications. > > > > > > Thanks, > > > > A. Mani > > Member, Cal. Math. Soc > > > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html Petr Pikal [EMAIL PROTECTED] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html