Originální popis anglicky:
modf, modff, modfl - decompose a floating-point number
Návod, kniha: POSIX Programmer's Manual
#include <math.h>
double modf(double
x, double
*iptr );
float modff(float
value, float
*iptr);
long double modfl(long double
value, long double
*iptr);
These functions shall break the argument
x into integral and fractional
parts, each of which has the same sign as the argument. It stores the integral
part as a
double (for the
modf() function), a
float (for
the
modff() function), or a
long double (for the
modfl()
function), in the object pointed to by
iptr.
Upon successful completion, these functions shall return the signed fractional
part of
x.
If
x is NaN, a NaN shall be returned, and *
iptr shall be set to a
NaN.
If
x is ±Inf, ±0 shall be returned, and *
iptr shall
be set to ±Inf.
No errors are defined.
The following sections are informative.
None.
The
modf() function computes the function result and *
iptr such
that:
a = modf(x, iptr) ;
x == a+*iptr ;
allowing for the usual floating-point inaccuracies.
None.
None.
frexp() ,
isnan() ,
ldexp() , the Base Definitions volume
of IEEE Std 1003.1-2001,
<math.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
