I have a matrix with 2 columns and n row. I need sort the matrix by the first column but the second row must be sort in the same order that the first column. Somebody know how I can sort this matrix. Thanks very much -- View this message in context: http://www.nabble.com/SORT-MATRIX-tp15955823p15955823.html Sent from the R help mailing list archive at Nabble.com.