HP-UX Reference (11i v1 05/09) - 3 Library Functions A-M (vol 6)

modf(3M) modf(3M)

NAME

modf( ) - decompose ﬂoating-point number

SYNOPSIS

#include <math.h>

double modf(double x, double *iptr);

DESCRIPTION

The modf() function breaks 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 in the object pointed to by iptr.

To use this function, make sure your program includes <

math.h>, and link in the math library by specify-

ing

-lm on the compiler or linker command line.

RETURN VALUE

Upon successful completion, the modf() function returns the signed fractional part of x.

If x is NaN,

modf() returns NaN.

If the correct value after rounding would be smaller in magnitude than MINDOUBLE, modf() returns

zero.

ERRORS

No errors are deﬁned.