How to check if the values in an array correspond to values in a cell array

Question

I have a cell array called grnPixels of size (1 x 40), where each individual cell has an M x 1 vector array of numbers where M is variable. I also have a single vector array called redCentroid of size N x 1.

I want to check if the values in redCentroid correspond to any values in grnPixels. I have made a code but it is extremely slow in this Matlab code. How can I improve this?

nRedCells = length(propsRed);
nGrnCells = length(propsGrn);
grnPixels = cell(1,nGrnCells);
redCentroid = zeros(nRedCells,1);
matchMemory = zeros(nRedCells,1);

for j = 1:nRedCells
    for i = 1:nGrnCells
        for n = 1:length(grnPixels{i})
            matchment = ismember(redCentroid(j),grnPixels{i}(n));
            if matchment == 1
                matchMemory(j,1:2) = [j i];
            end
            continue
        end
     end
 end

Sample Data

redCentroid

51756
65031
100996
118055
122055
169853
197175
233860
244415
253822

grnPixels{1}

142
143
100996
167
168

grnPixels{2}

537
538
539
540
541
542
233860
244415
545
546
547
548

Answer 1

ismember can accept a matrix for both the first or second input so there is no need for the outer loop or the most inner loop.

matchMemory = zeros(numel(redCentroid), 2);

for k = 1:numel(grnPixels)
    % Check which of the centroids are in grnpixels
    isPresent = ismember(redCentroid, grnPixels{k});

    % If they were present fill in the first column with the index in red
    matchMemory(isPresent, 1) = find(isPresent);

    % Fill in the second column with the index in green
    matchMemory(isPresent, 2) = k;
end