'Composite' mode has duplicate results (nearest neighbors not unique)

[Reederoo]

I wrote a Matlab function to check the uniqueness of the results index matrix and found that when the algorithm is 'composite', the results are up to 25% duplicate indices. None of the other algorithms produce any duplicate indices so I think this is a bug in 'composite'.

function avg_uniqueness = calculateUniqueness(result)
k = size(result,1); % The number of neighbors
n = size(result,2); % The number of query points
total_uniqueness = 0;
for i=1:n
% Count the number of unique neighbors for this query point
unique_count = length(unique(result(:, i)));
% Calculate the uniqueness fraction for this query point
uniqueness = unique_count / k;
% Add it to the total uniqueness
total_uniqueness = total_uniqueness + uniqueness;
end
% Calculate the average uniqueness
avg_uniqueness = total_uniqueness / n;
end

[stephematician]

Even though I don't have MATLAB I can confirm this.

This occurs when a CompositeIndex is searched without ensuring that a heap-based ResultSet is used; I'll add this to my fork (as it appears FLANN is not being updated anymore).