replace the rows of a matrix with binary digit values

Hello,

Consider the following matrix:

A=[ 1 1 1 1;2 2 2 2;3 3 3 3...]

The row sequence of 1 1 1 1, 2 2 2 2, 3 3 3 3 is repeating.

How can we change all the rows of

1 1 1 1 with 1 0 0 0

2 2 2 2 with 0 1 0 0

3 3 3 3 with 0 0 1 0

Thank you very much.

Best,

Pavlos

Answer 1

[Azzi Abdelmalek]

A=[ 1 1 1 1;2 2 2 2;3 3 3 3;2 2 2 2;3 3 3 3]
s=[1 0 0 0;0 1 0 0;0 0 1 0];
out=s(A(:,1),:)