Storing matrices value based on another matrix

I have a 5 by 5 matrix such as A =

0 1 0 0 0

1 0 0 0 1

2 0 0 0 0

0 0 0 0 0

0 0 1 0 0

And another column matrix B =

0.05

0.10

0.15

0.20

0.25

I have to solve the following problems

“If there is a non zero number in A matrix, it will look into same row of B matrix and store the B matrix number in another matrix named as C. If the non-zero number in A matrix is greater than 1, then it will store that number of times of B matrix same row value in C ”.

So, here C will be,

0.10 0.05 0.25 Nan 0.10

0.15 Nan Nan Nan Nan

0.15 Nan Nan Nan Nan

How can I write a code for C? Thanks in advance.

[dpb]

What have you done so far and where, specifically, did you have a particular ML question? We don't just solve homework problems w/o seeing effort being made.

The partial solution for C doesn't appear at all to match the output requested from the problem description, however.

[Rupayan Saha]

It's not a homework problem. I am working with large number data and in a part of the solution I need to calculate standard deviation from C matrix but at first I need to create C matrix. That is why I wrote the question this way with some simple form of matrix. I am trying to write down the code to create C matrix from A and B. I need help in this point.

Answer 1

[the cyclist]

Here is a straightforward algorithm:

[M,N] = size(A);

C = nan(max(sum(A,1)),N);

for jj = 1:N
    row = 1;
    for ii = 1:M
        idx = A(ii,jj);
        C(row:row+idx-1,jj) = B(ii);
        row = row+idx;
    end
end

[Rupayan Saha]

Thank you. It works perfectly.