HP C/iX Library Reference Manual (30026-90004)

262 Chapter5
HP C/iX Library Function Descriptions
modf
modf
Accepts a double value and splits the value into its integer and fractional parts.
Syntax
#include <math.h>
double modf (double value , double * iptr );
Parameters
value A real number input to the function.
iptr A pointer to a real number output from the function containing the integer
part of
value .
Return Values
n The signed fractional part of value .
Description
The modf function splits value into two parts, a fraction and an integer, such that
fraction + integer = value .
iptr points to a double variable where the integer part of value is to be stored. The
fractional part of
value is the return value of the function.
Example
The following program shows how to use the modf function:
main(argc, argv)
int argc;
char *argv[ ];
{
double value, iptr, frac, modf();
printf("Integer part: %g; Fractional part: %g\n", iptr, frac);
}
The program accepts one argument and prints the integer and fractional parts of that
value. Note that the address of
iptr is passed to modf(), because modf() expects the
address of a double variable where the integer part can be stored.
See Also
ANSI C 4.5.4.6, POSIX.1 8.1