find index of a matrix through another matrix

1 view (last 30 days)
I have this matrix A = [1 3 4 6 7] and B = [3 4] that it's a subset of A matrix. For example I would find the index of B matrix through A matrix. Having 3 as number I would know the index of 3 in matrix B.How can I do?

Answers (3)

Azzi Abdelmalek
Azzi Abdelmalek on 21 Sep 2012
Edited: Azzi Abdelmalek on 21 Sep 2012
B = [3 4]
idx=find(B==3)
  2 Comments
Azzi Abdelmalek
Azzi Abdelmalek on 21 Sep 2012
you have asked about index in B , what about A?
Salvatore Mazzarino
Salvatore Mazzarino on 21 Sep 2012
Because in my scripts I don't have directly A matrix.This is an example that permitted me to understand how find works.

Sign in to comment.


per isakson
per isakson on 21 Sep 2012
Edited: per isakson on 21 Sep 2012
This is possible if A and B are whole numbers
A = [ 1, 3, 4, 6, 7 ];
B = [ 3, 4 ];
ix1 = strfind( A, B );
ix2 = ix1 + numel(B) - 1;
all( B == A(ix1:ix2) )
If I understood you correct

Image Analyst
Image Analyst on 21 Sep 2012
Actually I thought first that what you meant was what per answered, but then I read your response to Azzi. I'm not sure you worded this correctly but when Azzi asked about it, you seemed to indicate it was worded exactly as you wanted. So in that case, I guess that would mean that if B is in A, the index of B (and you did say in B, not A) would always be 1. If B is not in A then there is no solution - obviously since B is not in A.

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!