search for a value in one matrix in another matrix

Hi everybody

Matrix A:

16 14 12 10 18

Matrix B:

2

3

5

4

1

new matrix :

2 14

3 12

5 18

4 10

1 16

For example, since 2 is written in matrix B, it prints the second row value in A next to 2 in the new matrix.

I need such a matrix. Could you help?

Thank u

Answer 1

[Voss]

% Matrix A:
A = [16    14    12    10    18];
% Matrix B:
B = [2; 3; 5; 4; 1];

% new matrix :
new_matrix = [B A(B).']

new_matrix = 5×2

2 14 3 12 5 18 4 10 1 16

[Berfin Çetinkaya]

actually in my real problem the data is different. There are multiple rows in matrix A. And the number of columns in matrix A is more than the number of rows in matrix B. I guess that's why when I tried to implement yours it gave an error.

For example, the matrices are:

Matrix A:

16 14 12 10 18 15 11 19

17 14 12 18 11 10 12 16

Matrix B:

6 15

3 12

5 18

4 10

8 19

As you can see, 1.2 values are not used. Also I just got the values in matrix A from the first row.

My real life matrix is much larger. I wanted to explain this with a simple example.

Is such a solution possible?

[Torsten]

@_'s code should also work for this case. You must have done something wrong in your code.

[Voss]

@Berfin Çetinkaya Do you mean like this? The difference here is that B is used to index into the first row of A.

% Matrix A:
A = [16    14    12    10    18    15    11    19; ...
     17    14    12    18    11    10    12    16];
% Matrix B:
B = [6; 3; 5; 4; 8];

% new matrix
new_matrix = [B A(1,B).'] % using only first row of A now

new_matrix = 5×2

6 15 3 12 5 18 4 10 8 19

[Berfin Çetinkaya]

yes I meant that. Thanks a lot of.

[Voss]

Excellent. You're welcome!