Strange results with floating-point comparison

Question

I have this simple test:

double h;
...
// code that assigns h its initial value, used below
...
if ((h>0) && (h<1)){
 //branch 1 -some computati         


        

Answer 1

Okay, you've posted the code. You are calculating h by a series of arithmetic operations from what looks like fairly arbitrary numbers. This means you're going to get a very close approximation to the ideal value of h, but not quite the right one.

This means that you need to do approximate comparisons. Testing (h == 1.0) will succeed only by accident; try (fabs(h - 1.0) < 1e-10) or something like that (using a const double instead of a magic number for tolerance). Make the appropriate changes for other comparisons.