is there a built-in synonym for function(v) length(unique(v)) ?? thanks -- Sam Steingold (http://sds.podval.org/) on Ubuntu 11.10 (oneiric) X 11.0.11004000 http://www.childpsy.net/ http://pmw.org.il http://iris.org.il http://ffii.org http://honestreporting.com http://openvotingconsortium.org Two wrongs don't make a right, but three rights make a left.