MATLAB Accumarray weighted mean

Question

So I am currently using \'accumarray\' to find the averages of a range of numbers wich correspond to matching ID\'s. Ex Input:

ID----Value
1     215
1     33         


        

Answer 1

Instead of using accumarray, you can directly compute a weighted mean, or many other functions, quite easily:

nIDs = length(unique(ID));
WeightedMean = zeros(nIDs, 1);

for ii = 1:nIDs
    iID = (ID == ii);
    WeightedMean(ii) = (Value(iID)' * Weight(iID)) / sum(Weight(iID));
end

Is there a specific reason you wish to do this through accumarray?