frexp(3C)

NAME

frexp(), ldexp(), modf() − split floating-point into mantissa and exponent

SYNOPSIS

DESCRIPTION

Every non-zero number can be written uniquely as x∗ 2n, where the “mantissa” (fraction) x is in the range 0.5 ≤ |x| < 1.0, and the “exponent” n is an integer.

frexp() returns the mantissa of a double value, and stores the exponent indirectly in the location pointed to by eptr. If value is zero, both results returned by frexp are zero.

ldexp() returns the quantity value∗ 2exp.

modf() returns the signed fractional part of value and stores the integral part indirectly in the location pointed to by iptr.

DIAGNOSTICS

If ldexp() would cause overflow, ±HUGE is returned (according to the sign of value), and errno is set to ERANGE .

If ldexp() would cause underflow, zero is returned and errno is set to ERANGE.

STANDARDS CONFORMANCE

frexp(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

ldexp(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C

modf(): AES, SVID2, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI C