# remainder

## PROLOG



           This manual page is part of the POSIX Programmer's Manual.  The
           Linux implementation of this interface may differ (consult the
           corresponding Linux manual page for details of Linux behavior), or
           the interface may not be implemented on Linux.
    


## NAME



           remainder, remainderf, remainderl — remainder function
    


## 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_);
    


## DESCRIPTION



           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.1‐2017 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.
    


## RETURN VALUE



           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 a NaN shall be returned.
    


## ERRORS



           These functions shall fail if:
    
           Domain Error
                       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:
    
           Domain Error
                       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.
    
           _The following sections are informative._
    


## EXAMPLES



           None.
    


## APPLICATION USAGE



           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.
    


## RATIONALE



           None.
    


## FUTURE DIRECTIONS



           None.
    


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