REMAINDER(3) Library Functions Manual REMAINDER(3)

remainder remainderf remainderl — remainder function

#include <math.h>

double remainder(double x, double y);
float remainderf(float x, float y);
long double remainderl(long double x, long double y);

The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.

These functions shall return the floating-point remainder r = x - ny when y is non-zero. The value n is the integral value nearest the exact value x / y. When | n - x / y |=½, the value n is chosen to be even.

The behavior of remainder () shall be independent of the rounding mode.

Upon successful completion, these functions shall return the floating-point remainder r = x - ny when y is non-zero.

On systems that do not support the IEC 60559 Floating-Point option, if y is zero, it is implementation-defined whether a domain error occurs or zero is returned.

If x or y is NaN, a NaN shall be returned.

If x is infinite or y is 0 and the other is non-NaN, a domain error shall occur, and either a NaN (if supported), or an implementation-defined value shall be returned.

These functions shall fail if:

[MX] The x argument is ±Inf, or the y argument is ±0 and the other argument is non-NaN.

If the integer expression ( math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [EDOM]. If the integer expression ( math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be raised.

These functions may fail if:

The y argument is zero.

If the integer expression ( math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to [EDOM]. If the integer expression ( math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be raised.

None.

On error, the expressions ( math_errhandling & MATH_ERRNO) and ( math_errhandling & MATH_ERREXCEPT) are independent of each other, but at least one of them must be non-zero.

None.

None.

abs(3) , div(3) , feclearexcept(3) , fetestexcept(3) , ldiv(3)

XBD V1_chap04(7) , <math.h>

First released in Issue 4, Version 2.

Moved from X/OPEN UNIX extension to BASE.

The remainder () function is no longer marked as an extension.

The () and () functions are added for alignment with the ISO/IEC 9899:1999 (“ISO C99”) standard.

The DESCRIPTION, RETURN VALUE, ERRORS, and APPLICATION USAGE sections are revised to align with the ISO/IEC 9899:1999 (“ISO C99”) standard.

IEC 60559:1989 standard floating-point extensions over the ISO/IEC 9899:1999 (“ISO C99”) standard are marked.

ISO/IEC 9899:1999 (“ISO C99”) standard, Technical Corrigendum 2 #55 (SD5-XSH-ERN-82) is applied.

January 1, 2008 posix.fail