Reference

sinpi(3)

half–cycle sine functions

NAME

sinpi, sinpif, sinpil – half–cycle sine functions

LIBRARY

Math Library (libm, -lm)

SYNOPSIS

#include <math.h>

double

sinpi(double x);

float

sinpif(float x);

long double

sinpil(long double x);

DESCRIPTION

The sinpi(), sinpif(), and sinpil() functions compute the sine of π × x. and measure angles in half-cycles.

RETURN VALUES

The sinpi(), sinpif(), and sinpil() functions returns sin(π × x). If x 2^(p - 1) where p is the floating–point precision of x, then the returned value is 0 and it has no significance.

SPECIAL VALUES

sinpi(0)

returns 0.

sinpi(n)

returns 0 for positive integers n.

sinpi(∞)

return an and raises an FE_INVALID exception.

sinpi()

return an and raises an FE_INVALID exception.

SEE ALSO

cos(3), cospi(3), fenv(3), math(3), sin(3), tan(3), tanpi(3)

AUTHORS

The half–cycle trignometric functions were written by Steven G. Kargl ⟨[email protected]⟩.

STANDARDS

These functions conform to IEEE Std 754-2008, to ISO/IEC TS 18661-4, "Information technology — Programming languages, their environments, and system software interfaces — Floating–point extensions for C" — Part 4: Supplementary functions, and to ISO/IEC 9899:2024 (“ISO C23”).

History