Hello, My program calculates several variables at each iteration and some of them are
integers and the rest are numeric. When I save them into a matrix, all of them are of numeric type, of course. I'm trying to find a way to save time/memory of my program and I was thinking that it might help to force some variables to be of integer type and the other columns numeric type. But when I actually tried it, I found it contrary. A list that has mixtures of integers and doubles are larger in size than a matrix that has only doubles. Do lists always take up more space than matrices if they have the same/similar variables? I just want to know it for the sake of efficiency. Thank you for your time. Kyeongmi My short test program is here: #matrix beta.mat <- matrix(0,nr=5, nc=2) for (i in 1:5){ beta.mat[i,] <- c(i,i*10.0) } #list gamma.mat <- list() for (i in 1:5){ gamma.mat$aa[i] <- i gamma.mat$bb[i] <- i*10.0 } object.size(beta.mat) #240 object.size(gamma.mat) #312 ______________________________________________ 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.