substitute values from one matrix to another

Suppose I have a matrix

A = [1 2;1 2;2 4;2 4];

and

B= [1 0.1;2 0.2];

I want to have a matrix 3 * 2 matrix C where *the first column of C is the first column of A *for each row, the value of the second column of C is the value of the second column of B that corresponds to the value of the first column of C.

Thus the output is

C = [1 0.1;1 0.1;2 0.2;2 0.2];

Please advise.

Answer 1

[Akira Agata]

How about using ismember function, like:

[~,loc] = ismember(A(:,1),B(:,1));
C = [A(:,1),B(loc,2)];