3-02-2012, 08:37 (-0800); Filoche escriu: > Hi every one. > > I'm learning how to use sapply (and other function of this family). > > Here's what I'm trying to do. > > I have a vector of lets say 5 elements. I also have a matrix of nX5. I would > like to know how many element by column are inferior to each element of my > vector. > > On this example: > v = c(1:5) > M = matrix(3,2,5) > > I would like to have a vector at the end which give me > > 0 0 0 2 2 >
This does that: > sapply(1:5, function(i) sum(M[,i] < v[i])) [1] 0 0 0 2 2 Basically, it's like a loop where at each iteration the function is called with one element of the vector 1:5 as argument, so what this really does is sum(M[,1] < v[1])) sum(M[,2] < v[2])) ... and then the results are put all together in a vector. -- Cheers, Ernest ______________________________________________ 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.
