search for: tp24458609p24458797

Hi, I have two matricies a and x: a<-matrix(c(3,4,5,2,3,4,1,1,2), nrow=3, ncol=3) [,1] [,2] [,3] [1,] 3 2 1 [2,] 4 3 1 [3,] 5 4 2 x<-matrix(c(3, NA, NA, NA, 2, 5, NA, 2, 2), nrow=3, ncol=3) [,1] [,2] [,3] [1,] 3 NA NA [2,] NA 2 2 [3,] NA 5 2 I wish to combine these two into one matrix using the values from x where x has values, and