Re: [Mingw-users] math.h fmod() problem

[Martin P. <pru...@gm...>]

On Wed, Nov 4, 2009 at 8:39 PM, myso <my...@se...> wrote:
> double value = fmod(range, tempSS); //the result was 0,04 which is wrong,
> because it should be zero

With a bit of debug gdb showed the MS supplied msvcrt in my computer
(0x77c2ced0 in msvcrt!fmod \(\) from C:\WINDOWS\system32\msvcrt.dll).
Since the msdn site for the function did not show any restriction
about the parameters this maybe are a MS problem.

> if(value != 0)
> {
>     //program jumped here so the zero doesn't seem to be a real zero
> }

You are right, this way is not safe to check floats and doubles, check
http://www.cygnus-software.com/papers/comparingfloats/Comparing%20floating%20point%20numbers.htm.

Martin