I think the following does what you want: probMatrix <- matrix(runif(5 * 5), 5, 5) binomialMatrix <- matrix(rbinom(5 * 5, 1, probMatrix), 5, 5)
Patrick Burns [EMAIL PROTECTED] +44 (0)20 8525 0696 http://www.burns-stat.com (home of S Poetry and "A Guide for the Unwilling S User") Economics Guy wrote: >I am having a little trouble getting R to do something without writing >a couple of very awkward loops. > >I have a matrix of probabilities and I want to generate a new matrix >of ones and zeros where each element in the new matrix is the result >of a draw from a binomial distribution where the probability of >getting a 1 is the corresponding element in the matrix of >probabilities. > >Example Code: >-------------------------------------------- > >## First I generate the matrix of probabilities for example purposes. > >probMatrix <- matrix(NA,5,5){ > >for (i in 1:5) > >probVectorI <- runif(5,0,1) > >probMatrix[i,] <- probVectorI > >} > ># Now I want to take each element in probMatrix and use it as the >probability parameter in rbinom draw and generate a new matrix. >Something like this: > >binomialMatrix <- rbinom(1,1,probMatrix) > ># But that does not work. I know I can run a loop across each vector >of the matrix, but this seems like an bad way to do this. > >---------------------------End Code-------------------------------- > >So any help would be appreciated. > >Thanks, > >EG > >______________________________________________ >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.
