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
#include <math.h>
double floor (double x);
float floorf (float x);
double ceil (double x);
float ceilf (float x);
double modf (double x, double *n);
float modff (float x, float *n);
double nint (double x);
float nintf (float x);
double rint (double x);
float rintf (float x);
double trunc (double x);
float truncf (float x);
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.
The floor() and floorf() functions return the largest floating-point integer value less than or equal to x.
The ceil() and ceilf() functions return the smallest floating-point integer value greater than or equal to x.
The modf() and modff() 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() and modff() functions return f and store i into the location pointed to by n.
The nint() and nintf() 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() and rintf() functions round x to an integral value according to the current IEEE rounding direction specified by the user.
The trunc() and truncf() functions truncate x to an integral value. delim off