Find minimum difference between matrices.
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I have two matrices. For each element in the first matrix, I want to find the closest value in the second matrix, and then take the difference, which will be recorded in a third matrix. Any thoughts on the best way to do this? Thank you.
Azzi Abdelmalek on 18 Jun 2013
Edited: Azzi Abdelmalek on 18 Jun 2013
%If you do not allow repetition
Matt Kindig on 18 Jun 2013
Edited: Matt Kindig on 18 Jun 2013
Another way using histc() function (may be faster for large matrices).
A = rand(5,5); %first matrix
B = rand(2,3); %second matrix
B = sort(B(:)); %make B vector and sort for binning convenience
edges = B(1:(end-1)) + 0.5*diff(B); %"edges" are halfway between each B span
edges= [-inf; edges; inf]; %add +/- inf at ends to include all values
[~,whichBin] = histc(A, edges); %get which bin contains each A
% for each value in A, the value in B which is closest to A
%will fall between bin edges k and k+1 (i.e., k-th element of B)
%third matrix is difference between A and the B for that bin
DiffAB = A - B(whichBin);
EDIT: changed to allow A and B to be matrices as well (consistent with Azzi's solution).