How do I do floating point Remainder function in C++?

[Mr. Ken]

Morning, group:

How do I code floating point modulus function?
What I need is

double a;
double b;
double c;

a = 2.3;
b = 1.2;

c = a % b; // invalid operands of types `double' and `int' to binary `

TIA.

 

[Phlip]

http://www.opengroup.org/onlinepubs/007908799/xsh/fmod.html ?

 

[Mr. Ken]

http://www.opengroup.org/onlinepubs/007908799/xsh/fmod.html ?

Thankk you.

 

[persenaama]

a - b*int(a/b) or fmod() should do the trick.

 

[Gernot Frisch]

a - b*int(a/b) or fmod() should do the trick.

when b == 0, you're busted. When a/b > MAX_INT, the result is wrong.

Use fmod, which basically does:
f = a/b - floor(a/b);

 

[persenaama]

std::fmod even better.