finding the minimum between 3 numbers

Question

How can I find the smallest number among three that is non zero.

I tried introducing a very small number eps = 1e-6 (my numbers are either zero or clearly larger than eps) and doing tests between min(x,eps), min(y,eps) etc. I didn't get anything. Is there a way to do that with a function?

Answer 1

numbers = [1 3 4 -2 1 0];
answer = min(numbers(numbers>0));

answer == 1

Answer 2

If the numbers are all stored in a vector x you could do the following:

x = [1 0 2 0 3 0 4];
y = min(x(x>0));

This is based on your statement that

numbers are either zero or clearly larger than eps

If you mean larger in magnitude and you want to accept non-zero negative values you could use:

x = [1 0 -2 0 3 0 4];
y = min(x(x~=0));

Note that this will return the most negative number when negative numbers are present, rather than the number with the smallest non-zero magnitude. To get the number with the smallest non-zero magnitude, you could use:

x = [1 0 -2 0 3 0 4];
xnonzero = x(x~=0);
[~,idx] = min(abs(xnonzero));
y = xnonzero(idx);

It doesn't seem very elegant. There is probably a more direct way.