Counting Number of Positive & Negative Numbers

I have a script that is "suppose" to count how many positive and negative number in "column a" and put that total into column "Amount Positive" and "Amount Negative". However...my script is not doing that completely, as it apparently only counts the number in the column and doesn't sort it accordingly. Where did I go wrong?

resize(lcount, 0);

for #i in 1 .. numvalues(twothetadiff) loop

lcount += 1;

     if TwoThetaDiff <= 0 then

           num_negative := lcount;

     end if;

     if twothetadiff >= 0 then

           num_positive := lcount;

     end if;

end loop;

Thanks,

jlalb

Edit: the values I am comparing are either positive or negative .0004547 (random number)