NAME

       modf, modff, modfl - extract signed integral and fractional values from floating-point number

SYNOPSIS

       #include <math.h>

       double modf(double x, double *iptr);
       float modff(float x, float *iptr);
       long double modfl(long double x, long double *iptr);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       modff(), modfl():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

       These  functions  break the argument x into an integral part and a fractional part, each of which has the
       same sign as x.  The integral part is stored in the location pointed to by iptr.

RETURN VALUE

       These functions return the fractional part of x.

       If x is a NaN, a NaN is returned, and *iptr is set to a NaN.

       If x is positive infinity (negative infinity), +0 (-0) is returned, and *iptr is set to positive infinity
       (negative infinity).

ERRORS

       No errors occur.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).
       ┌──────────────────────────┬───────────────┬─────────┐
       │ Interface                │ Attribute     │ Value   │
       ├──────────────────────────┼───────────────┼─────────┤
       │ modf(), modff(), modfl() │ Thread safety │ MT-Safe │
       └──────────────────────────┴───────────────┴─────────┘

CONFORMING TO

       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO

       frexp(3), ldexp(3)

COLOPHON

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                                                   2017-09-15                                            MODF(3)