Hi, lst1<- lapply(letters[1:3],function(i) {df1<-data.frame(my_df[i],my_df["dat"]); res<-ddply(df1,.(df1[[i]]),function(x) c("mean"=mean(x$dat),"n"=nrow(x)));names(res)[1]<-i;res<-res[res[,1]==1,]})
res1<-Reduce(function(...) merge(...,all=TRUE),lst1) res1[is.na(res1)]<-"*" res1 # mean n a b c #1 11 3 1 * * #2 12 3 * * 1 #3 14 3 * 1 * A.K. ----- Original Message ----- From: Alexander Shenkin <ashen...@ufl.edu> To: r-help@r-project.org Cc: Sent: Wednesday, March 20, 2013 3:57 PM Subject: [R] summarize dataframe based on multiple cols, not their combinations Hi folks, I'm trying to figure out how to get summarized data based on multiple columns. However, instead of giving summaries for every combination of categorical columns, I want it for each value of each categorical column regardless of the other columns. I could do this with three different commands, but i'm wondering if there's a more elegant way that I'm missing. Thanks! allie > my_df = data.frame(a = c(1,1,1,0,0,0), b=c(0,0,0,1,1,1), c=c(1,0,1,0,1,0), dat=c(10,11,12,13,14,15)) > my_df a b c dat 1 1 0 1 10 2 1 0 0 11 3 1 0 1 12 4 0 1 0 13 5 0 1 1 14 6 0 1 0 15 > # not what I want > ddply(my_df, .(a,b,c), function(x) c("mean"=mean(x$dat), "n"=nrow(x))) a b c mean n 1 0 1 0 14 2 2 0 1 1 14 1 3 1 0 0 11 1 4 1 0 1 11 2 What I want: a b c mean n 1 1 * * 11 3 2 * 1 * 14 3 3 * * 1 12 3 where "*" refers to any value of the other columns. ______________________________________________ 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. ______________________________________________ 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.