How to quickly obtain the row indices in the original matrix A for a sub-matrix B?

Dear All,

I have an original matrix A and a sub-matrix which is formed by selected rows from A. Now given A and B, how can I find out the row indices of B in A?

For example,

A = [

0 0 1 0 -1

2 -1 0 0 0

-1 0 -1 0 0

0 0 3 -1 -1

0 0 -1 1 0

0 0 -1 0 1

];

B = [

0 0 1 0 -1

0 0 3 -1 -1

0 0 -1 1 0

0 0 -1 0 1

];

The indices should be ind = [1 4 5 6].

Thanks a lot.

Benson

Answer 1

[Stephen23]

[~,Y] = ismember(B,A,'rows')

Y = 4×1

1 4 5 6

[Benson Gou]

Hi, Stephen,

Thanks a lot for your great help. It works very well.

Benson