Greg, I take it that you're trying to generate a random correlation matrix, so first create a covariance matrix,
p = 6 v = matrix(rnorm(p*p), ncol=p) cov = t(v) %*% v Then convert it to a correlation matrix, cov2cor(cov) HTH. Horace >>> Gregory Gentlemen <[EMAIL PROTECTED]> 7/29/2007 7:31:36 PM >>> Greetings, I have a seemingly simple task which I have not been able to solve today and I checked all of the help archives on this and have been unable to find anything useful. I want to construct a symmetric matrix of arbtriray size w/o using loops. The following I thought would do it: p <- 6 Rmat <- diag(p) dat.cor <- rnorm(p*(p-1)/2) Rmat[outer(1:p, 1:p, "<")] <- Rmat[outer(1:p, 1:p, ">")] <- dat.cor However, the problem is that the matrix is filled by column and so the resulting matrix is not symmetric. I'd be grateful for any adive and/or solutions. Gregory --------------------------------- [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.