How do I add certain numbers from one cell to another?

CA = {[5 -10 2],[6 6 8],[0 9 -10 8 -10 3]};
CB = {[4 17 2],[6 6 10],[9 3 4 9 7 6]};
CC = {[1 2 4],[4 2 1],[1 7 3 1 2 2]};
for i = 1:length(CA)
    idx = CA{i}==-10 ;
    CB{i}(idx) = CB{i}(idx)+15 ;
end

The output I want is the "new" CB generated in the for loop. But now instead of adding 15 to all of them, I want to add different numbers to each depending on "CC."

For example:

Just looking at the first group of each cell:

CA = {[5 -10 2]}

CB = {[4 17 2]}

CC = {[1 2 4]}

I would like to add the difference between the "1 and 4" in CC (l1-4l=3), to the "17" in CB.

So the first group in the "new" CB will be {[4 20 2]}.

BTW. I chose the numbers "1 and 4" in CC because they are the numbers that would be adjacent to the -10 in CA.

Answer 1

[Pratik]

Hi Austin,

To achieve the desired outcome, you need to identify the indices of -10 in CA, then find the adjacent numbers in CC at those indices, calculate their absolute difference, and add this difference to the corresponding elements in CB. Here's how you can implement this:

CA = {[5 -10 2], [6 6 8], [0 9 -10 8 -10 3]};
CB = {[4 17 2], [6 6 10], [9 3 4 9 7 6]};
CC = {[1 2 4], [4 2 1], [1 7 3 1 2 2]};

for i = 1:length(CA)
    idx = find(CA{i} == -10); % Find indices of -10 in CA{i}
    for j = 1:length(idx)
        if idx(j) > 1 && idx(j) < length(CC{i})
            % Calculate the absolute difference of adjacent numbers in CC
            difference = abs(CC{i}(idx(j) - 1) - CC{i}(idx(j) + 1));
            % Add this difference to the corresponding element in CB
            CB{i}(idx(j)) = CB{i}(idx(j)) + difference;
        end
    end  
end

% Display the modified CB
disp(CB);

    {[4 20 2]}    {[6 6 10]}    {[9 3 10 9 8 6]}

Explanation:

• Finding Indices:
• Use find(CA{i} == -10) to locate indices of -10 in each cell array within CA.
• For each index of -10, check if it is not the first or last element to ensure it has adjacent elements.
• Calculate the absolute difference between the adjacent elements in CC.
• Add the calculated difference to the corresponding element in CB.