I am using > prop.table(m,1) and > prop.table(m,2) my aim. which I think is the most 'easy' way. Thanks. Casper -- View this message in context: http://r.789695.n4.nabble.com/how-to-divide-each-column-in-a-matrix-by-its-colSums-tp3062739p3062797.html Sent from the R help mailing list archive at Nabble.com.