Excuse me if this is has been discussed before, but, How can I make the cos(pi/2) = 0 (instead of on my machine 6.123234e-17) and the sin(pi) = 0 (instead of 1.224647e-16 on my machine) ? I'd like sin(pi) == 0 to return TRUE, and is zapsmall appropriate here? -------------- next part -------------- A non-text attachment was scrubbed... Name: brian.vcf Type: text/x-vcard Size: 411 bytes Desc: Card for Brian O'Gorman Url : https://stat.ethz.ch/pipermail/r-help/attachments/20000308/9eb8072b/brian.vcf