pub fn primitive_float_sin_with_period<T>(x: T, u: u64) -> Twhere
Float: From<T> + PartialOrd<T>,
for<'a> T: ExactFrom<&'a Float> + RoundingFrom<&'a Float> + PrimitiveFloat,Expand description
Computes $\sin(2\pi x/u)$, the sine of a primitive float measured in $u$ths of a turn (so that
u = 360 is degrees).
$$ f(x,u) = \sin(2\pi x/u)+\varepsilon. $$
- If $x$ is not finite or $u=0$, $\varepsilon$ may be ignored or assumed to be 0.
- If $x$ is finite and $u\neq 0$, then $|\varepsilon| < 2^{\lfloor\log_2 |\sin(2\pi
x/u)|\rfloor-p}$, where $p$ is the precision of the output (24 if
Tis af32and 53 ifTis af64).
Special cases:
- $f(\text{NaN},u)=\text{NaN}$
- $f(\pm\infty,u)=\text{NaN}$
- $f(x,0)=\text{NaN}$
- $f(\pm0.0,u)=\pm0.0$
- If $x/u$ is a multiple of $1/2$, the result is exactly $0.0$ with the sign of $x$ (following
IEEE 754-2019’s
sinPi, so that the function is odd); if it is an odd multiple of $1/4$, the result is exactly $1$ or $-1$; and if it is $\pm1/12$ or $\pm5/12$ modulo $1$, the result is exactly $1/2$ or $-1/2$.
Overflow is not possible, since the result lies in $[-1, 1]$. The result underflows, to a
subnormal or to zero, only when $2\pi x/u$ does, which takes a subnormal $x$ or a large $u$; no
f32 or f64 is close enough to a half turn, without being one, for its sine to be
subnormal.
§Worst-case complexity
Constant time and additional memory.
§Examples
use malachite_base::num::float::NiceFloat;
use malachite_float::float::arithmetic::sin::primitive_float_sin_with_period;
assert!(primitive_float_sin_with_period(f32::NAN, 360).is_nan());
assert!(primitive_float_sin_with_period(f32::INFINITY, 360).is_nan());
assert!(primitive_float_sin_with_period(1.0f32, 0).is_nan());
assert_eq!(
NiceFloat(primitive_float_sin_with_period(-0.0f32, 360)),
NiceFloat(-0.0)
);
assert_eq!(
NiceFloat(primitive_float_sin_with_period(90.0f32, 360)),
NiceFloat(1.0)
);
assert_eq!(
NiceFloat(primitive_float_sin_with_period(30.0f64, 360)),
NiceFloat(0.5)
);
assert_eq!(
NiceFloat(primitive_float_sin_with_period(1.0f32, 7)),
NiceFloat(0.7818315)
);
assert_eq!(
NiceFloat(primitive_float_sin_with_period(1.0f64, 7)),
NiceFloat(0.7818314824680298)
);