#### 20.8.4 Remainder Functions

The functions in this section compute the remainder on division of two floating-point numbers. Each is a little different; pick the one that suits your problem.

— Function: double fmod (double numerator, double denominator)

> — Function: float fmodf (float numerator, float denominator)

> > — Function: long double fmodl (long double numerator, long double denominator)

> > > Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.

> > > These functions compute the remainder from the division of numerator by denominator. Specifically, the return value is numerator`-` n`*` denominator``, where n is the quotient of numerator divided by denominator, rounded towards zero to an integer. Thus, `fmod (6.5, 2.3)` returns `1.9`, which is `6.5` minus `4.6`.

> > > The result has the same sign as the numerator and has magnitude less than the magnitude of the denominator.

> > > If denominator is zero, `fmod` signals a domain error.

— Function: double drem (double numerator, double denominator)

> — Function: float dremf (float numerator, float denominator)

> > — Function: long double dreml (long double numerator, long double denominator)

> > > Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.

> > > These functions are like `fmod` except that they round the internal quotient n to the nearest integer instead of towards zero to an integer. For example, `drem (6.5, 2.3)` returns `-0.4`, which is `6.5` minus `6.9`.

> > > The absolute value of the result is less than or equal to half the absolute value of the denominator. The difference between `fmod (`numerator`,` denominator`)` and `drem (`numerator`,` denominator`)` is always either denominator, minus denominator, or zero.

> > > If denominator is zero, `drem` signals a domain error.

— Function: double remainder (double numerator, double denominator)

> — Function: float remainderf (float numerator, float denominator)

> > — Function: long double remainderl (long double numerator, long double denominator)

> > > Preliminary: | MT-Safe | AS-Safe | AC-Safe | See POSIX Safety Concepts.

> > > This function is another name for `drem`.