You can also do it from first principles: outer(1:100,1:100,`<`) * m
which generalizes nicely to >, <=, >=, !=, etc. -s On 11/21/08, Henrique Dallazuanna <[EMAIL PROTECTED]> wrote: > See ?upper.tri and ?lower.tri. ______________________________________________ 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.