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primitive_float_sin

Function primitive_float_sin 

Source
pub fn primitive_float_sin<T>(x: T) -> T
where Float: From<T> + PartialOrd<T>, for<'a> T: ExactFrom<&'a Float> + RoundingFrom<&'a Float> + PrimitiveFloat,
Expand description

Computes $\sin x$, the sine of a primitive float. Using this function is more accurate than using the default sin function or the one provided by libm.

$$ f(x) = \sin x+\varepsilon. $$

  • If $x$ is not finite, $\varepsilon$ may be ignored or assumed to be 0.
  • If $x$ is finite, then $|\varepsilon| < 2^{\lfloor\log_2 |\sin x|\rfloor-p}$, where $p$ is the precision of the output (24 if T is a f32 and 53 if T is a f64).

Special cases:

  • $f(\text{NaN})=\text{NaN}$
  • $f(\pm\infty)=\text{NaN}$
  • $f(\pm0.0)=\pm0.0$

Overflow is not possible, since the result lies in $[-1, 1]$. The result is subnormal only when $x$ is, and then it is $x$ itself: no f32 or f64 is close enough to a nonzero multiple of $\pi$ for its sine to be subnormal.

§Worst-case complexity

Constant time and additional memory.

§Examples

use malachite_base::num::basic::traits::NegativeInfinity;
use malachite_base::num::float::NiceFloat;
use malachite_float::float::arithmetic::sin::primitive_float_sin;

assert!(primitive_float_sin(f32::NAN).is_nan());
assert!(primitive_float_sin(f32::INFINITY).is_nan());
assert!(primitive_float_sin(f32::NEGATIVE_INFINITY).is_nan());
assert_eq!(NiceFloat(primitive_float_sin(0.0f32)), NiceFloat(0.0));
assert_eq!(NiceFloat(primitive_float_sin(-0.0f32)), NiceFloat(-0.0));
assert_eq!(
    NiceFloat(primitive_float_sin(1.0f32)),
    NiceFloat(0.84147096)
);
assert_eq!(
    NiceFloat(primitive_float_sin(1.0f64)),
    NiceFloat(0.8414709848078965)
);