pow

Calculates x^y.

Special Values
x	y	pow(x, y)	div 0	invalid?
anything	±0.0	1.0	no	no
\|x\| > 1	+∞	+∞	no	no
\|x\| < 1	+∞	+0.0	no	no
\|x\| > 1	-∞	+0.0	no	no
\|x\| < 1	-∞	+∞	no	no
+∞	> 0.0	+∞	no	no
+∞	< 0.0	+0.0	no	no
-∞	odd integer > 0.0	-∞	no	no
-∞	> 0.0, not odd integer	+∞	no	no
-∞	odd integer < 0.0	-0.0	no	no
-∞	< 0.0, not odd integer	+0.0	no	no
±1.0	±∞	-NaN	no	yes
< 0.0	finite, nonintegral	NaN	no	yes
±0.0	odd integer < 0.0	$(PLUSMNINF)	yes	no
±0.0	< 0.0, not odd integer	+∞	yes	no
±0.0	odd integer > 0.0	±0.0	no	no
±0.0	> 0.0, not odd integer	+0.0	no	no

Unqual!F pow(F x, G n)
typeof(Unqual!(F).init * Unqual!(G).init) pow(F x, G n)
real pow(I x, F y)
Unqual!(Largest!(F, G)) pow(F x, G y)
@nogc @trusted pure nothrow
Unqual!(Largest!(F, G))
pow
(
F
G
)
(
F x
,
G y
)
if (
isFloatingPoint!(F) &&
isFloatingPoint!(G)
)

Examples

import std.math.operations : isClose;

assert(isClose(pow(2.0, 3.0), 8.0));
assert(isClose(pow(1.5, 10.0), 57.6650390625));

// square root of 9
assert(isClose(pow(9.0, 0.5), 3.0));
// 10th root of 1024
assert(isClose(pow(1024.0, 0.1), 2.0));

assert(isClose(pow(-4.0, 3.0), -64.0));

// reciprocal of 4 ^^ 2
assert(isClose(pow(4.0, -2.0), 0.0625));
// reciprocal of (-2) ^^ 3
assert(isClose(pow(-2.0, -3.0), -0.125));

assert(isClose(pow(-2.5, 3.0), -15.625));
// reciprocal of 2.5 ^^ 3
assert(isClose(pow(2.5, -3.0), 0.064));
// reciprocal of (-2.5) ^^ 3
assert(isClose(pow(-2.5, -3.0), -0.064));

// reciprocal of square root of 4
assert(isClose(pow(4.0, -0.5), 0.5));

// per definition
assert(isClose(pow(0.0, 0.0), 1.0));

import std.math.operations : isClose;

// the result is a complex number
// which cannot be represented as floating point number
import std.math.traits : isNaN;
assert(isNaN(pow(-2.5, -1.5)));

// use the ^^-operator of std.complex instead
import std.complex : complex;
auto c1 = complex(-2.5, 0.0);
auto c2 = complex(-1.5, 0.0);
auto result = c1 ^^ c2;
// exact result apparently depends on `real` precision => increased tolerance
assert(isClose(result.re, -4.64705438e-17, 2e-4));
assert(isClose(result.im, 2.52982e-1, 2e-4));

pow

Examples

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