# remainderf(3) [netbsd man page]

```REMAINDER(3)						   BSD Library Functions Manual 					      REMAINDER(3)

NAME
remainder, remainderf, remquo, remquof -- remainder functions

LIBRARY
Math Library (libm, -lm)

SYNOPSIS
#include <math.h>

double
remainder(double x, double y);

float
remainderf(float x, float y);

double
remquo(double x, double y, int *quo);

float
remquof(float x, float y, int *quo);

DESCRIPTION
Provided that y != 0 , the remainder() and remainderf() functions calculate the floating-point remainder r of

r = x - ny,

where n is the integral value nearest to the exact value of x / y.  If

| n - x / y | = 1/2 ,

the value n is chosen to be even.	Consequently, the remainder is computed exactly and | r | <= | y | / 2 .

Also the remquo() and remquof() functions calculate the remainder as described above.  But these additionally use quo to store a value whose
sign is the sign of x / y and whose magnitude is congruent modulo 2^k to the magnitude of the integral quotient of x / y, where k is an
implementation-defined integer greater than or equal to 3.

The rationale of the remquo() family of functions relates to situations where only few bits of the quotient are required.	The exact repre-
sentation of the quotient may not be meaningful when x is large in magnitude compared to y.

RETURN VALUES
The functions return the remainder independent of the rounding mode.  If y is zero , NaN is returned and a domain error occurs.  A domain
error occurs and a NaN is returned also when x is infinite but y is not a NaN.  If either x or y is NaN, a NaN is always returned.

div(3), fast_remainder32(3), fmod(3), math(3)

STANDARDS
The described functions conform to ISO/IEC 9899:1999 (``ISO C99'').

BSD								September 18, 2011							       BSD```

## Check Out this Related Man Page

```REMAINDER(3)						   BSD Library Functions Manual 					      REMAINDER(3)

NAME
remainder, remainderf, remainderl, remquo, remquof, remquol -- minimal residue functions

LIBRARY
Math Library (libm, -lm)

SYNOPSIS
#include <math.h>

double
remainder(double x, double y);

float
remainderf(float x, float y);

long double
remainderl(long double x, long double y);

double
remquo(double x, double y, int *quo);

float
remquof(float x, float y, int *quo);

long double
remquol(long double x, long double y, int *quo);

DESCRIPTION
remainder(), remainderf(), remainderl(), remquo(), remquof(), and remquol() return the remainder r := x - n*y where n is the integer nearest
the exact value of x/y; moreover if |n - x/y| = 1/2 then n is even.  Consequently the remainder is computed exactly and |r| <= |y|/2.  But
attempting to take the remainder when y is 0 or x is +-infinity is an invalid operation that produces a NaN.

The remquo(), remquof(), and remquol() functions also store the last k bits of n in the location pointed to by quo, provided that n exists.
The number of bits k is platform-specific, but is guaranteed to be at least 3.