pub fn primitive_float_compound<T>(x: T, n: i64) -> Twhere
Float: From<T> + PartialOrd<T>,
for<'a> T: ExactFrom<&'a Float> + RoundingFrom<&'a Float> + PrimitiveFloat,Expand description
Computes the compound function $(1+x)^n$ of a primitive float and an i64, returning a
primitive float.
The result is correctly rounded to the nearest value.
$$ f(x,n) = (1+x)^n+\varepsilon. $$
- If $(1+x)^n$ is infinite, zero, or
NaN, $\varepsilon$ may be ignored or assumed to be 0. - If $(1+x)^n$ is finite and nonzero, then $|\varepsilon| < 2^{\lfloor\log_2 (1+x)^n\rfloor-p}$,
where $p$ is the precision of the output (typically 24 if
Tis af32and 53 ifTis af64, but less if the output is subnormal).
Special cases:
- $f(\text{NaN},n)=\text{NaN}$ if $n\neq 0$, and $1.0$ if $n=0$
- $f(-\infty,n)=\text{NaN}$, even if $n=0$
- $f(\infty,0)=1.0$
- $f(\infty,n)=\infty$ if $n>0$, and $0.0$ if $n<0$
- $f(\pm 0.0,n)=1.0$
- $f(x,n)=\text{NaN}$ if $x<-1$, even if $n=0$
- $f(-1.0,n)=1.0$ if $n=0$, $0.0$ if $n>0$, and $\infty$ if $n<0$
- $f(x,0)=1.0$ if $x\geq -1$
The result is never negative. If the result overflows, $\infty$ is returned, and if it underflows, $0.0$ is returned.
§Worst-case complexity
Constant time and additional memory.
§Examples
use malachite_base::num::float::NiceFloat;
use malachite_float::float::arithmetic::compound::primitive_float_compound;
assert_eq!(NiceFloat(primitive_float_compound(0.5, 2)), NiceFloat(2.25));
assert_eq!(
NiceFloat(primitive_float_compound(0.1, 10)),
NiceFloat(2.5937424601)
);
assert_eq!(
NiceFloat(primitive_float_compound(-0.5, -2)),
NiceFloat(4.0)
);