MATLAB: How can i find cumulative mean inside a for loop

for loopmean

Hey everyone,
I have a code which helps me to calculate the mean values. Each of the "cellList.meshData(j)" corresponds to a single column vector of values. I would like it to give me the total mean of all 25 cells. The following code gives me the mean for each cell.
for j=1:25
    data=cellList.meshData(j);
    if isempty(data{1,1})
        continue
    end
mean_int_val = mean(cellList.meshData{j}{1,1}.signal2);
end

Best Answer

Hi,
For your situation, you should consider that . So they are 2 situations:
  1. All vectors have the same size
  2. Vectors can have different sizes
If you are in the first situation, I would simply keep all mean_int_val and simply recompute the the mean of all means.
nData = 25;
mean_int_val = NaN(1, nData);
for j=1:nData
    data=cellList.meshData(j);
    if isempty(data{1,1})
        continue
    end
    mean_int_val(j) = mean(cellList.meshData{j}{1,1}.signal2);
end
mean_total = mean(mean_int_val, 'omitnan');
If you are in the second situation, I would also keem the number of samples and then compute the mean.
nData = 25;
mean_int_val = NaN(1, nData);
mean_size    = NaN(1, nData);
for j=1:nData
    data=cellList.meshData(j);
    if isempty(data{1,1})
        continue
    end
    mean_int_val(j) = mean(cellList.meshData{j}{1,1}.signal2);
    mean_size(j)    = numel(cellList.meshData{j}{1,1}.signal2);
end
mean_total = sum(mean_int_val .* mean_size) / sum(mean_size);
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