modf(3C)
NAME
modf, modff − decompose floating-point number
SYNOPSIS
#include <math.h>
double modf(double x, double ∗iptr);
float modff(float x, float ∗iptr);
DESCRIPTION
The modf() and modff() functions break the argument x into integral and fractional parts, each of which has the same sign as the argument. modf() stores the integral part as a double in the object pointed to by iptr. modff() stores the integral part as a float in the object pointed to by iptr.
RETURN VALUES
Upon successful completion, modf() and modff() return the signed fractional part of x.
If x is NaN, NaN is returned and ∗iptr is set to NaN.
If the correct value would cause underflow to 0.0, modf() returns 0 and errno may be set to ERANGE.
ERRORS
The modf() function may fail if:
ERANGE The result underflows.
USAGE
An application wishing to check for error situations should set errno to 0 before calling modf(). If errno is non-zero on return, or the return value is NaN, an error has occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | MT-Safe |
SEE ALSO
frexp(3C), isnan(3M), ldexp(3C), attributes(5)
SunOS 5.6 — Last change: 29 Dec 1996