FLOOR(3M)		       Silicon Graphics			     FLOOR(3M)



NAME
     floor, ffloor, floorf, ceil, fceil, ceilf,	fmod, fmodf, fabs, fabsf,
     rint, trunc, ftrunc, truncf - floor, ceiling, remainder, absolute value,
     nearest integer, and truncation functions

SYNOPSIS
     #include <math.h>

     double floor (double x);
     float ffloor (float x);
     float floorf (float x);

     double ceil (double x);
     float fceil (float	x);
     float ceilf (float	x);

     double trunc (double x);
     float ftrunc (float x);
     float truncf (float x);

     double fmod (double x, double y);
     float fmodf (float	x, float y);

     double fabs (double x);
     float fabsf (float	x);

     double rint(double	x);

DESCRIPTION
     The fmod, fabs, and trunc functions listed	above, as well as the single-
     precision versions	of the remaining functions, are	only available in the
     standard math library, -lm.

     The floor functions return	the largest integer not	greater	than x.	 The
     argument x	is double for floor, and float for ffloor and its ANSI-named
     equivalent	floorf.

     The ceil functions	return the smallest integer not	less than x.  The
     argument x	is double for ceil, and	float for fceil	and its	ANSI-named
     equivalent	ceilf.

     The trunc functions return	the integer (represented as a floating-point
     number) of	x with the fractional bits truncated.  The argument x is
     double for	trunc, and float for ftrunc.

     fabs returns the absolute value of	the double x, |x|.  It also has	a
     counterpart of type float,	namely fabsf.

     rint returns the integer (represented as a	double precision number)
     nearest its double	argument x in the direction of the prevailing rounding
     mode.  rint has no	counterpart which accepts an argument of type float.




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FLOOR(3M)		       Silicon Graphics			     FLOOR(3M)



     fmod returns the floating-point remainder of the division of its double
     arguments x by y.	It returns a number f with the same sign as x, such
     that x = iy + f for some integer i, and |f| < |y|.	 Hence both the
     invocations
	  fmod(2.5,1.0)
	  fmod(2.5,-1.0)
     yield 0.5,	while the two invocations
	  fmod(-2.5,1.0)
	  fmod(-2.5,-1.0)
     yield -0.5.
     fmodf is the counterpart of fmod which accepts and	returns	values of type
     float.

DIAGNOSTICS
     In	the diagnostics	below, functions in the	standard math library libm.a,
     are referred to as	-lm versions, and those	in the the BSD math library
     libm43.a, are referred to as -lm43	versions.  The -lm versions always
     return the	default	Quiet NaN and set errno	to EDOM	when a NaN is used as
     an	argument.  A NaN argument usually causes the -lm43 versions to return
     the same argument.	 The -lm43 versions never set errno.
     The value of HUGE_VAL is IEEE Infinity.

     If	y (and,	possibly, x) are zero, or if x is +/-HUGE_VAL, the fmod
     functions return a	quiet NaN, and set errno to EDOM.
     If	the quantity x/y would overflow, the fmod functions may	return zero,
     without setting errno.

     A version of the double-precision fabs function exists in the C library
     as	well.  The C library version may not behave correctly when the input
     is	NaN.

NOTES
     In	the default rounding mode, to nearest, rint(x) is the integer nearest
     x with the	additional stipulation that if |rint(x)-x|=1/2 then rint(x) is
     even.  Other rounding modes can make rint act like	floor, or like ceil,
     or	round towards zero.

     Another way to obtain an integer near x is	to declare (in C)
	  double x;	int k;	  k = x;
     The C compilers round x towards zero to get the integer k.	 Also note
     that, if x	is larger than k can accommodate, the value of k and the
     presence or absence of an integer overflow	are hard to detect.

SEE ALSO
     abs(3C), math(3M)










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