how can i change the columns in the matrix? For example I wanna change 2nd and 3rd column

M = [1     2     3     4; ...
     2     4     6     8; ...
     3     6     9    12];

[Jan]

I've brushed up your text a little bit.

Does "change" mean changing the values or interchanging the columns itself?

[Hassan F]

If you mean interchange, as Jan pointed out, you can something like this. say M has 3 columns:

M=M(:,[1 3 2]);

Check help for indexing matrices.

[Image Analyst]

How about you change them both to zeros? Next time, give an example of what you want your output to be so people won't have to guess.

Answer 1

[Thorsten]

A = rand(4); % sample matrix

B = A(:, [1 3 2 4]