Full_Name: Steven King Version: 1.16 OS: OSX vesion 10.4.8 Submission from: (NULL) (71.126.161.149) Setting a matrix is a function - the failure occurs only on 2 X 2 matrices. x<-matrix(1:4,nrow=2) > x [,1] [,2] [1,] 1 3 [2,] 2 4 > x[x]<-2 Error: subscript out of bounds