Mysterious error using array division in a for loop

I need to make a for loop in MATLAB to divide each column in a matrix by a separate column vector. I only want to do this for a selection of the columns in the matrix, not all the columns.

This is what I'd like to do, where Indexes is a 19x1 vector of integers (not all consecutive numbers), big_matrix is 82x24, and other_column is 82x1:

    matrix_to_fill = zeros(82,length(Indexes));
    for x = Indexes
        new_column = big_matrix(:,x)./other_column;
        new_index = find(Indexes==x);
        matrix_to_fill(:,new_index) = new_column;
    end

When I run this I get the following error:

    Error using  ./ 
    Matrix dimensions must agree.

I can run each iteration separately without getting errors, so I know that the matrix dimensions agree. What's more, if I type out the Indexes as a vector it works fine:

    matrix_to_fill = zeros(82,length(Indexes));
    for x = [1,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,23]
        new_column = big_matrix(:,x)./other_column;
        new_index = find(Indexes==x);
        matrix_to_fill(:,new_index) = new_column;
    end

And I think the "x=Indexes" syntax is fine because I've tested that using just:

    for x = Indexes
        disp(x)
    end

So I'm completely stumped. Any help would be much appreciated!

Answer 1

[Walter Roberson]

Your Indices needs to be a row vector for that to work. If it is a column vector then x will get all of the values at the same time.