There are some errors in your script:
Only gives the number 0.0015 as output, if you want that i goes from -0.0015 to 0.0015 with steps of 0.00001 use:
in your for loop i is not an integer so you cannot use deltau(i), the same hold for u(i) and s(i).
maybe you should use this:
and two 'end' commands are missing in your script.