How to limit a function to return results only above some threshold

Hi everyone, Assume:

a = [1 2 3]
b = [4 5 6]
c = [7 8 9]
D = myFunction(a, b, c)

The function returns n by 3 matrix, where n depends on a, b and c. I have encountered a problem when, for some a, b and c, the resulting matrix is very big, the Matlab doesn't want to continue the calculation saying:

Requested 67108864x26 (13.0GB) array exceeds maximum array size preference...

Is there a way to restrict the function to output results only above some certain level in, say, column #3. For example, like so:

D = D(D(:,3)>0.01,:)

This won't work in my case, since the restriction performed after myFunction has been executed. Is there a way to tell the program, that I want myFunction stop calculation when value of 3rd column gets lower than 0.01? Or maybe there is some other solution for this problem?

Thanks.

[Walter Roberson]

Like

if all(D(:,3)<0.01);
  return
end

??