HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

fmod(3M) fmod(3M)

NAME

fmod( ), fmodf( ) - remainder functions

SYNOPSIS

#include <math.h>

double fmod(double x, double y);

float fmodf(float x, float y);

DESCRIPTION

The fmod() function returns the ﬂoating-point remainder ( f ) of the division of x by y, where f has the

same sign as x, such that x = iy + f for some integer i, and |f|<|y|.

fmodf() is a float version of fmod()

; it takes float arguments and returns a float result. To

use this function, compile either with the default

-Ae option or with the -Aa and -D_HPUX_SOURCE

options.

fmodf() is not speciﬁed by any standard, but it is named in accordance with the conventions speciﬁed in

the "Future Library Directions" section of the ANSI C standard.

To use these functions, make sure your program includes <math.h>, and link in the math library by speci-

fying -lm on the compiler or linker command line.

RETURN VALUE

If y is ±INFINITY and x is not ±INFINITY,

fmod() returns x.

If x is ±zero and y is a nonzero number,

fmod() returns x.

If x or y is NaN, fmod() returns NaN.

If the correct value after rounding would be smaller in magnitude than MINDOUBLE, fmod() returns

zero.

If y is zero,

fmod() returns NaN and sets errno to [EDOM].

If x is ±INFINITY, fmod() returns NaN and sets

errno to [EDOM].

ERRORS

fmod() fails, errno is set to one of the following values.

[EDOM] y is zero.

[EDOM] x is ±INFINITY.