Use Jeff’s solution. This doesn’t account for ties. > On Feb 26, 2015, at 1:11 PM, Don McKenzie <d...@u.washington.edu> wrote: > > Kate — here is a transparent solution (tested but without NA treatment). > Doubtless there are cleverer faster ones, which later posters will present. > > HTH > > # example with four columns and 20 rows > nrows <- 20 > > A <- sample(c(1:100), nrows, replace=T) > B <- sample(c(1:100), nrows, replace=T) > C <- sample(c(1:100), nrows, replace=T) > D <- sample(c(1:100), nrows, replace=T) > > locs <- > c(c(1:nrows)[A==max(A)],c(1:nrows)[B==max(B)],c(1:nrows)[C==max(C)],c(1:nrows)[D==max(D)]) > > mat1 <- matrix(rep(0,4*nrows),nrows,4) > for (i in 1:4) > mat1[,i][locs[i]] <- 1 > SUM <- rowSums(mat1) > > >> On Feb 26, 2015, at 12:23 PM, Kate Ignatius <kate.ignat...@gmail.com> wrote: >> >> Hi, >> >> Supposed I had a data frame like so: >> >> A B C D >> 0 1 0 7 >> 0 2 0 7 >> 0 3 0 7 >> 0 4 0 7 >> 0 1 0 0 >> 0 0 0 0 >> 0 0 0 0 >> 0 0 0 0 >> 0 0 1 5 >> 0 5 1 5 >> 0 4 1 5 >> 0 8 4 7 >> 0 0 3 0 >> 0 0 3 4 >> 0 0 3 4 >> 0 0 0 5 >> 0 2 0 6 >> 0 0 4 0 >> 0 0 4 0 >> 0 0 4 0 >> >> For each row, I want to count how many max column values appear to >> adventurely get the following outcome, while ignoring zeros and N/As: >> >> A B C D Sum >> 0 1 0 7 1 >> 0 2 0 7 1 >> 0 3 0 7 1 >> 0 4 0 7 1 >> 0 1 0 0 0 >> 0 0 0 0 0 >> 0 0 0 0 0 >> 0 0 0 0 0 >> 0 0 1 5 0 >> 0 5 1 5 0 >> 0 4 1 5 0 >> 0 8 4 7 3 >> 0 0 3 0 0 >> 0 0 3 4 0 >> 0 0 3 4 0 >> 0 0 0 5 0 >> 0 2 0 6 0 >> 0 0 4 0 1 >> 0 0 4 0 1 >> 0 0 4 0 1 >> >> I've used the following code but it doesn't seem to work (my sum >> column column is all 1s): >> >> (apply(df,1, function(x) (sum(x %in% c(pmax(x)))))) >> >> Is this code too simple? >> >> Thanks! >> >> K. >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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 -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.
