Hi I'm trying to set up a simulation problem without resorting to (m)any loops. I want to set entries in a data frame of zeros ('starts' in the code below) to 1 at certain points and the points have been randomly generated and stored in a separate data.frame ('sl'), which has the same number of columns.
An example of the procedure is as follows: ml <- data.frame(matrix(sample(1:50,80, replace=TRUE),20,4)) mm <- apply(ml, 2, cumsum) starts<- data.frame(matrix(0,600,4)) I can achieve the result I want with a loop: for (i in 1:4){ lstarts[,i][mm[,i]] <-1 } But as I want to use a large number of columns I would like to do away with the loop Can anyone suggest how this might be done? Thanks in advance Brett Robinson ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit http://www.symanteccloud.com ______________________________________________________________________ [[alternative HTML version deleted]] ______________________________________________ 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.