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frexp(3)

NAME

frexp, ldexp, modf − split into mantissa and exponent

SYNTAX

double frexp(value, eptr)
double value;
int *eptr;

double ldexp(value, exp)
double value;
int exp;

double modf(value, iptr)
double value, *iptr;

DESCRIPTION

The frexp subroutine returns the mantissa of a double value as a double quantity, x, of magnitude less than 1, and stores an integer n such that value = x*2**n indirectly through eptr. 

The ldexp subroutine returns the quantity value*2**exp. 

The modf subroutine returns the positive fractional part of value and stores the integer part indirectly through iptr. 

DIAGNOSTICS

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

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026