Substituing values of a matrix

Hi everyone! I'm working on substituing values of a matrix with the values of another matrix. So for example, if I had

    A = [1 2 3 ; 2 4 5 ; 4 1 3];
    V = [1 10 ; 2 20 ; 3 30 ; 4 40 ; 5 50];

I'd like to substitue the values of A that are equal to the values of the first column of V, with the value of the second column of V. For the example, change in A 1 by 10, 2 by 20 and so on. Thank you!

Answer 1

[Andrei Bobrov]

out = reshape(V(A,2),size(A));

[Alyssa Webb]

I'm getting this error: Index exceeds matrix dimensions.

[Alyssa Webb]

OK, I solved it using just the second column of V and

out = reshape(V(A),size(A));

Thank you!

[Jan]

@Alyssa Webb: Without your example data this works without an error. The first column of your V seems to be the index 1:n, and then Andrei's suggestion is a very efficient look-up-table approach.

Answer 2

[Jan]

A = [1 2 3 ; 2 4 5 ; 4 1 3];
V = [1 10 ; 2 20 ; 3 30 ; 4 40 ; 5 50];

[match, index] = ismember(A(:), V(:, 1));
A(match)       = V(index, 2)