MATLAB Answers

Find values and positions of a matrix referring to another matrix

35 views (last 30 days)
Hi !!! Good day.
I hope you can help me
I have two matrices
A = [2 4 7];
B = [3 4 6
     1 5 7
     2 8 9
     9 2 4];
From the first element of matrix A find position and value in the first column of matrix B
From the second element of matrix A find position and value in the second column of matrix B
From the third element of matrix A find position and value in the third column of matrix B
In the end I will have two vectors;
one with the values 2, 4, 7 and the other with the positions 3, 1, 2
In reality, matrix A is 1 X 18 and matrix B has 720 X 18
Thank you very much for your help.
Regards.

  0 Comments

Sign in to comment.

Accepted Answer

More Answers (1)

Stephen Cobeldick
Stephen Cobeldick on 1 Oct 2019
Edited: Stephen Cobeldick on 1 Oct 2019
This is MATLAB, so you should learn how to efficiently solve tasks like this without loops:
>> A = [2,4,7];
>> B = [3,4,6;1,5,7;2,8,9;9,2,4];
>> X = bsxfun(@eq,A,B); % or for >=R2016b simply X = A==B;
>> V = B(X)
V =
2
4
7
>> [R,~] = find(X)
R =
3
1
2