[Kjetil Brinchmann Halvorsen] >erf [in] package (CRAN) NORMT3, as help.search("error function") could >have told [you] It does not for me. I would presume one needs NORMT3 installed first, and NORMT3 is seemingly not part of standard base R installation. -- François Pinard http://pinard.progiciels-bpi.ca