data <- data.frame(var1=c(1,2,3), var2=c(3,4,5), var3=c(4,5,6), foo = c(100,200,300)) # sum rows with "var" in their name rowSums(data[, grep("var", names(data))])
1 2 3 8 11 14 [EMAIL PROTECTED] wrote: > I have a dataframe called "data" with 5 records (in rows) each of > which has been scored on each of many variables (in columns). > > Five of the variables are named var1, var2, var3, var4, var5 using > headers. The other variables are named using other conventions. > > I can create a new variable called var6 with the value 15 for each > record with this code: > > >> var6=var1+var2+var3+var4+var5 >> > > but this is tedious for my real dataset with dozens of variables. I > would rather use a wildcard to add up all the variables that begin > with "Var" like this pseudocode: > > >> Var6=sum(var*) >> > > Any suggestions for implementing this in R? Thanks! Mark > > ______________________________________________ > 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 > > -- Simon Blomberg, B.Sc.(Hons.), Ph.D, M.App.Stat. Centre for Resource and Environmental Studies The Australian National University Canberra ACT 0200 Australia T: +61 2 6125 7800 email: Simon.Blomberg_at_anu.edu.au F: +61 2 6125 0757 CRICOS Provider # 00120C ______________________________________________ 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