NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | STANDARDS | HISTORY | BUGS | EXAMPLES | SEE ALSO |
|
|
remainder(3) Library Functions Manual remainder(3)
drem, dremf, dreml, remainder, remainderf, remainderl - floating- point remainder function
Math library (libm, -lm)
#include <math.h> double remainder(double x, double y); float remainderf(float x, float y); long double remainderl(long double x, long double y); /* Obsolete synonyms */ [[deprecated]] double drem(double x, double y); [[deprecated]] float dremf(float x, float y); [[deprecated]] long double dreml(long double x, long double y); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): remainder(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 500 || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE remainderf(), remainderl(): _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE drem(), dremf(), dreml(): /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
These functions compute the remainder of dividing x by y. The return value is x-n*y, where n is the value x / y, rounded to the nearest integer. If the absolute value of x-n*y is 0.5, n is chosen to be even. These functions are unaffected by the current rounding mode (see fenv(3)). The drem() function does precisely the same thing.
On success, these functions return the floating-point remainder, x-n*y. If the return value is 0, it has the sign of x. If x or y is a NaN, a NaN is returned. If x is an infinity, and y is not a NaN, a domain error occurs, and a NaN is returned. If y is zero, and x is not a NaN, a domain error occurs, and a NaN is returned.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur: Domain error: x is an infinity and y is not a NaN errno is set to EDOM (but see BUGS). An invalid floating- point exception (FE_INVALID) is raised. These functions do not set errno for this case. Domain error: y is zero errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
For an explanation of the terms used in this section, see attributes(7). ┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │drem(), dremf(), dreml(), │ Thread safety │ MT-Safe │ │remainder(), remainderf(), │ │ │ │remainderl() │ │ │ └──────────────────────────────────────┴───────────────┴─────────┘
remainder() remainderf() remainderl() C11, POSIX.1-2008. drem() dremf() dreml() None.
remainder() remainderf() remainderl() C99, POSIX.1-2001. drem() 4.3BSD. dremf() dreml() Tru64, glibc2.
Before glibc 2.15, the call remainder(nan(""), 0); returned a NaN, as expected, but wrongly caused a domain error. Since glibc 2.15, a silent NaN (i.e., no domain error) is returned. Before glibc 2.15, errno was not set to EDOM for the domain error that occurs when x is an infinity and y is not a NaN.
The call "remainder(29.0, 3.0)" returns -1.
div(3), fmod(3), remquo(3)
Linux man-pages 6.04 2023-03-30 remainder(3)
Pages that refer to this page: div(3), fma(3), fmod(3), remquo(3)