search for: makematrix

dear all, i have a quite simple question, i want to fill up a Matrix like done in the following function, but the performance is very bad for large dimensions is there a way to do this like with apply or something similar? makeMatrix <- function(a, b,dim) { X=matrix(0,ncol=dim,nrow=dim) for (i in c(1:dim)){ for (j in c(1:dim)) { if (i==j) {X[i,j]<-a} else { X[i,j]<- exp(( -1*abs(i-j))/(3*b)) } } } X } -- View this message in context: http://r.789695.n4.nabble.com/fill-Matrix-quicker-tp3710428p3710428.h...