Hi, I was having trouble developing a looping function in a selection simulation that I'm trying to develop and I was hoping if someone could help. Basically, I have a matrix with a random generated numbers representing scores on the variables. The rows represent applicants and columns represent the variables. # Number of variables p<-5 # Number of applicants n_ap<-100 # Create random scores for the applicants across five variables z<-rnorm(n_ap*p,0,1) #Put z into a matrix dim(z)<-c(n_ap,p) #Rank applicant scores on variable X1 d1 <- rev(order(z[,1])) #Rank applicant scores on variable X2 d2 <- rev(order(z[,2])) #Rank applicant scores on variable X3 d3 <- rev(order(z[,3])) #Rank applicant scores on variable X4 d4 <- rev(order(z[,4])) #Rank applicant scores on variable X5 d5 <- rev(order(z[,5])) pool <- cbind(d1,d2,d3,d4,d5) Is there a way to specify a vector of selection ratio (e.g. sr<-c(.10,.20,.30) ) and use this in a loop so that the function will produce a matrix of applicants who will be selected when the selection ratio is .10, .20, and .30? Thank you and please leave a post if more info is needed -- View this message in context: http://n4.nabble.com/selection-simulation-tp1575587p1575587.html Sent from the R help mailing list archive at Nabble.com.