Hi all, as a small step towards removing some clutter and redundancy, the functions "log.na" and "sqr" have been removed from the vsn package, development version (1.5.1). The log.na function (and many other similar ones) can still be found in the marray package. It simply provides a version of the log function that does not throw warnings when called with non-positive arguments: log.na = function (x, ...) log(ifelse(x > 0, x, NA), ...) Best wishes Wolfgang ------------------------------------- Wolfgang Huber European Bioinformatics Institute European Molecular Biology Laboratory Cambridge CB10 1SD England Phone: +44 1223 494642 Http: www.dkfz.de/abt0840/whuber