fmod

fmod, fmodf, fmodl - floating-point remainder function

#include <math.h>
 I double fmod(double  x , double  y );

I float fmodf(float  x , float  y );

I long double fmodl(long double  x , long double  y );

Link with -lm.

The R fmod () function computes the remainder of dividing x by y. The return value is x - n * y, where n is the quotient of x / y, rounded towards zero to an integer.

The R fmod () function returns the remainder, unless y is zero, when the function fails and errno is set.

EDOM

SVr4, 4.3BSD, C89. The float and long double variants are C99 requirements.

remainder(3)