How to replace repeating values for each column by NaN?

Hi!

I am a Matlab newbie, and I have a problem replacing repeating values for each column.

For example: Let's say I have matrix:

1 2 3 4

2 3 4 4

3 1 3 1

3 1 3 2

And the desired output would then be:

1 2 3 4

2 3 4 NaN

3 1 3 1

NaN NaN NaN 2

Hope this makes sense,

Kr, Markus

Answer 1

[Jan]

A = [1    2    3    4; ...
     2    3    4    4; ...
     3    1    3    1; ...
     3    1    3    2];
M    = [false(1, width(A)); diff(A, 1) == 0];
A(M) = NaN

A = 4×4

1 2 3 4 2 3 4 NaN 3 1 3 1 NaN NaN NaN 2

[Markus Niemelä]

Thanks, that seemed to work nicely!