[R] calculating column difference in a matrix

Dear R users; Consider the following toy example: a - matrix(c(2,3,4,NA,NA,5,8,NA,8,NA), 5, 2) b - cbind(a,apply(a, 1, diff, na.rm = TRUE)) What I would like be able to get is: c - matrix(c(2,3,4,NA,NA,5,8,NA,8,NA,3,5,-4,8,NA), 5, 3) i.e., for each row if both values (column 1 and 2) are NA

Re: [R] calculating column difference in a matrix

. - Original Message - From: Pedro Mardones mardone...@gmail.com To: R-help@r-project.org Cc: Sent: Wednesday, March 13, 2013 5:43 PM Subject: [R] calculating column difference in a matrix Dear R users; Consider the following toy example: a - matrix(c(2,3,4,NA,NA,5,8,NA,8,NA), 5, 2) b