floor(3) — Subroutines

NAME

floor, ceil, modf, nint, rint, trunc − Round floating-point numbers to floating-point integers, return the nearest integral value, and truncate a floating-point number

LIBRARY

Math Library (libm.a)

SYNOPSIS

#include <math.h>

double floor   (double x);
float floorf (float x);
long double floorl   (long double x);
double ceil    (double x);
float ceilf   (float x);
long double ceill    (long double x);
double modf    (double x, double ∗n);
float modff   (float x, float ∗n);
long double modfl    (long double x, long double ∗n);
double nint    (double x);
float nintf   (float x);
long double nintl    (long double x);
double rint    (double x);
float rintf   (float x);
long double rintl    (long double x);
double trunc   (double x);
float truncf (float x);
long double truncl   (long double x);

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

floor(): XPG4

ceil(): XPG4

modf(): XPG4

rint(): XPG4−UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION

The floor(), floorf(), and floorl() functions return the largest floating-point integer value less than or equal to x.

The ceil(), ceilf(), and ceill() functions return the smallest floating-point integer value greater than or equal to x.

The modf(), modff(), and modfl() functions split a floating-point number x into a fractional part f and an integer part i such that |f| < 1.0 and (f + i) = x. Both f and i have the same sign as x. The modf(), modff(), and modfl() functions return f and store i into the location pointed to by n.

The nint(), nintf(), and nintl() functions return the nearest integral value to x, except halfway cases are rounded to the integral value larger in magnitude. This corresponds to the FORTRAN generic intrinsic function nint().

The rint(), rintf(), and rintl() functions round x to an integral value according to the current IEEE rounding direction specified by the user.