MATLAB: How to find closest values in array)

array

I want to find closest numbers in array as shown in example a=[4 7 8 9 10 11 20 23 26 27 28 29 30 60] output first group 7 8 9 10 11 second group 26 27 28 29 30

Best Answer

If you have the Image Processing Toolbox, you can use bwlabel to give an "ID number" to each group that has the minimum spacing. Then you can extract each of those labeled groups one at a time and put into a cell array.
a=[4 7 8 9 10 11 20 23 26 27 28 29 30 60] % Original, easy case: separate groups
% a=[4 7 8 9 10 11 12 25 26 27 28 29 30 60] % Tricky test case: groups adjacent/touching
% a=[6 7 8 9 10 11 12 25 26 27 28 29 30 31] % Tricky test case: groups touch each other and ends
diffs = diff(a)
minSpacing = min(diffs)
binaryLabels = diffs == minSpacing
% Label the groups
labeledgroups = bwlabel(binaryLabels)
% Extract each group
for k = 1 : max(labeledgroups)
  thisGroupsIndexes = find(labeledgroups == k);
  % Tack one more.
  thisGroupsIndexes = [thisGroupsIndexes, thisGroupsIndexes(end)+1]
  % Extract these elements from the original "a" vector
  result{k} = a(thisGroupsIndexes)
end
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