Find values and positions of a matrix referring to another matrix

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.

Answer 1

[David Hill]

for i=1:length(A)
C(i)=find(B(:,i)==A(i),1);%will there always be only one match?
end

[Ricardo Gutierrez]

Many thanks !!!!

It worked

Answer 2

[Stephen23]

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

[Ricardo Gutierrez]

Many thanks !!!!

It worked