Find index to rows of one matrix in another

Suppose I have two matrices:

>> A = eye(3)

A =

1     0     0
0     1     0
0     0     1

>> idx = [1 3 2 2];
>> B = A(idx, :)

B =

1     0     0
0     0     1
0     1     0
0     1     0

But I don't know idx. How would I find the vector idx such that isequal(B, A(idx, :))?

I found answers for calculating the index of one row at a time:

>> find(ismember(A, B(2,:), 'rows'))

ans =

3

Answer 1

[Bill Tubbs]

I figured out the answer:

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

idx =

1
3
2
2

In case you want to check that all rows in B where found in A you can do this:

[matches, idx] = ismember(B, A, 'rows')
assert(all(matches))