trim is for calculating trimmed mean such that "the fraction (0 to 0.5) of observations to be trimmed from each end of x before the mean is computed" from ?help(mean) Ozgur -- View this message in context: http://r.789695.n4.nabble.com/Usage-of-trim-in-mean-tp4643281p4643293.html Sent from the R help mailing list archive at Nabble.com.