How to compare two array in nested loop ?

I have code like this :

Ind = [];
distTh = 5; 
A = [1;7;14];
B = [2;5;8;10]; 
for i = 1:size(A,1)
  for j = 1: size(B,1)
      Distance = abs(B(j) - A(i));
      if Distance < distTh
          Ind = [Ind j];
      end
  end
end

My questions : How to make elements in array 'B' no longer compared to array 'A' (remove index 'B'), if it is already in 'Ind' ?

Thank you very much.

Answer 1

[Geoff Hayes]

Joni - well you can use find or ismember to check to see whether you should add j to the list of indices Ind as

      if Distance < distTh && ~ismember(j, Ind)
          Ind = [Ind j];
      end

or use a similar check to skip the compare altogether

for i = 1:size(A,1)
  for j = 1: size(B,1)
      if ~isempty(find(Ind == j))
          continue;
      end
      Distance = abs(B(j) - A(i));
      if Distance < distTh
          Ind = [Ind j];
      end
  end
end

There are probably other ways to solve this too. Can you give us an idea as to how large your A and B matrice might be? (As this will impact performance and help you decide which method to use (find vs ismember, etc.).

[Joni Saputra]

Thank you Sir. It's work.