NAME

frexp, ldexp, modf − split into mantissa and exponent

SYNOPSIS

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

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

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

DESCRIPTION

Frexp returns the mantissa of value as a double quantity, x, of magnitude less than 1; x is less than 0.5 only if value is denormal. 
 
Frexp also stores in ∗eptr an integer n such that value = x∗2n. 

Ldexp returns the quantity value∗2exp by calling scalb with the same arguments. 

Modf returns the fractional part of value and stores the integer part in ∗iptr. 

DIAGNOSTICS

Frexp returns sign(x) ∗ 0.5 and stores 50000 in ∗eptr when x is infinite; it returns a NaN and stores 0 in ∗eptr when x is a NaN, and returns 0 and stores 0 in ∗eptr when x is 0. 

Ldexp sets errno to ERANGE on overflow or underflow. 

Modf returns 0 and stores x in ∗iptr when x is infinite; it returns x and stores x in ∗iptr when x is a NaN. 

SEE ALSO

ieee(3)

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  15 Dec 1986