Does anyone know if there is an R function that will take a matrix like this
jim 1 0 0 0 0 0 jim 0 1 0 0 0 0 jim 0 0 1 0 0 0 bob 1 0 0 0 0 0 bob 0 0 1 0 0 0 harry 0 0 1 0 0 0 harry 0 0 0 1 0 0 harry 0 0 0 0 1 0 harry 0 0 0 0 0 1 and make it like this? (that is, add together rows that have the same name?) jim 1 1 1 0 0 0 bob 1 0 1 0 0 0 harry 0 0 1 1 1 1 here's the code I started with, if it helps library (dummies) a <- c(1,1,1,2,2,3,3,3,3) b<- c("A","B","C","A","C","C","D","E","F") name<- c("jim", "jim", "jim", "bob", "bob", "harry", "harry", "harry", "harry") MyMat <- cbind (a, b) rownames (MyMat) <- name dum.mat.temp <- dummy ("b", MyMat) #dum.mat.temp <-cbind (name, dum.mat.temp) # if you want names as a column dum.mat.temp Many thanks in advance! --Sarah ______________________________________________ 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.