Datasheet

Floating-point Support

5.4.18 Scale a number by a power of two (scalb, scalbn)

double scalb(double x, double n);

double scalbn(double x, int n);

These functions return x times two to the power n. The difference between the functions

is whether n is passed in as an

int

or as a

double

scalb

is the same function as the

Scalb

function described in the IEEE 754 Appendix.

Its behavior when n is not an integer is undefined.

5.4.19 Return the fraction part of a number (significand)

double significand(double x);

This function returns the fraction part of x, as a number between 1.0 and 2.0 (not

including 2.0).

5.4.20 Bessel functions of the second kind (y0, y1, yn)

double y0(double x);

double y1(double x);

double yn(int, double);

These functions compute Bessel functions of the second kind.

and

compute the

functions of order 0 and 1 respectively.

computes the function of order n.

If x is positive and exceeds π times 2

, these functions return an

ERANGE

error, denoting

total loss of significance in the result.