How to retrieve unique columns in a matrix ?

I would like to retrieve all the unique columns in a matrix..

If my matrix =

1 -1 1 1

1 1 1 1

2 1 1 1

UniqueColumns =

1 -1 1

1 1 1

2 1 1

Thank you before hand.

Answer 1

[Stephen23]

A = [1,-1,1,1;1,1,1,1;2,1,1,1];
B = unique(A.','rows','stable').'

B = 3×3

1 -1 1 1 1 1 2 1 1

[Laxmikant Sharma]

What if you want the indeces too?

[B idx] = unique(A.', 'rows', 'stable').'

Not working!!!

[Stephen23]

"What if you want the indeces too?"

A = [1,-1,1,1;1,1,1,1;2,1,1,1];
[B,idx] = unique(A.','rows','stable');
B = B.'

B = 3×3

1 -1 1 1 1 1 2 1 1

idx

idx = 3×1

1 2 3