How to get specific value?

A = [5 2 3 8 7 1 2 2 3]
[labeledA, numRegions] = bwlabel(A < 4)
% Get the size of the regions.
props = regionprops(labeledA, 'Area')
elementCounts = [props.Area]

In the command window:

A =
   5     2     3     8     7     1     2     2     3
labeledA =
   0     1     1     0     0     2     2     2     2
numRegions =
   2
props = 
2×1 struct array with fields:
  Area
elementCounts =
   2     4

And I get sth like this:

elementCounts =
 2     4
value = 
2 3 1 2 2 3

Answer 1

[Andrei Bobrov]

One way:

A = [5 2 3 8 7 1 2 2 3]';
b = A < 4;
ii = bwlabel(b);
elementCounts = accumarray(ii(ii>0),1)
value = A(b)

[Justyna Slawska]

how to get value when elementCounts==1 (only 1)

[Andrei Bobrov]

out =  A(find(elementCounts == 1) == ii)