Debugging Session

(Originally posted on Doug's MATLAB Video Tutorials blog.)

The below code does not behave as expected. The values in the middle of the vector are zeroed out. This debugging session figures out why this happens.

clear
num = [1 1 1 1 1 1 1];
den = [1 2 3 0 5 6 7];
for i = 1: numel(den)
    if den(i) == 0
        a = 1
    else
        a(i) = num(i)/den(i)
    end
end
plot(a,'o-')