Replacing elements in matrix columns

Hi,

I have a matrix 61312*3, and I want to replace the element of the 2nd and 3rd column by some numbers. For example, in 2nd and 3rd column, I need to replace

34 by 1

10, 17, 22, 39, and 59 by 2

and so on.

How should I proceed? Thanks in advance.

Answer 1

[Chris McComb]

You can do the replacement using logical indexing. The replacement for 34 --> 1 would be as follows:

for i=2:3
  idx = (mat(:,i) == 34);
  mat(idx,i) = 1;
end