which(matrix(rnorm(30), ncol=3) > 1, arr.ind = TRUE) See ?which Ivan Yegorov wrote: > Could you please help me. How can I get indexes of matrix elements equal to the specified value. Thanks in advance. -- Chuck Cleland, Ph.D. NDRI, Inc. 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 452-1424 (M, W, F) fax: (917) 438-0894