MATLAB: How to get the indices of the values inside every bin i.e. histcounts2

density functionhistogramindexprobability

How to get the indices of x and y for the counts that go into every bin.
x = randn(1,10); y = randn(1,10);
nbins = [8 8]; 
[C,Xedges,Yedges] = histcounts2(x,y, nbins); 
C
C =
     0     0     0     1     0     1     0     1
     0     0     1     1     0     0     0     0
     0     0     0     3     0     0     0     0
     0     0     0     0     0     0     0     0
     0     0     1     0     0     0     0     0
     0     0     0     0     0     0     0     0
     0     0     0     0     0     0     0     0
     1     0     0     0     0     0     0     0
     
     [C,Xedges,Yedges, binX, binY] = histcounts2(x,y, nbins); 
     binX(3), binY(4) %will give the opposite, in which bin is element x(3) y(4)

Best Answer

Suppose you want to know which elements are in the bin that is 8 down and 6 across. Then
binToFind = [8 6];
[tf,loc] = ismember([binX',binY'],binToFind,'row')
idx = find(loc)
idx gives the indices you want. It will be an empty vector if there are no elements in that bin.
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