public function testNoZeroZero()
{
$zero = DecimalConstants::Zero();
$one = DecimalConstants::One();
$nTwo = Decimal::fromInteger(-2);
$pTwo = Decimal::fromInteger(2);
$this->assertTrue($nTwo->pow($zero)->equals($one));
$this->assertTrue($pTwo->pow($zero)->equals($one));
}
/**
* Returns the square root of this object
* @param integer $scale
* @return Decimal
*/
public function sqrt($scale = null)
{
if ($this->isNegative()) {
throw new \DomainException("Decimal can't handle square roots of negative numbers (it's only for real numbers).");
} elseif ($this->isZero()) {
return DecimalConstants::Zero();
}
$sqrt_scale = $scale !== null ? $scale : $this->scale;
return self::fromString(bcsqrt($this->value, $sqrt_scale + 1), $sqrt_scale);
}
/**
* @expectedException \DomainException
* @expectedExceptionMessage Infinite elevated to zero is undefined.
*/
public function testNegativeInfiniteZeroPower()
{
InfiniteDecimal::getNegativeInfinite()->pow(DecimalConstants::Zero());
}
/**
* Powers this value to $b
*
* @param Decimal $b exponent
* @param integer $scale
* @return Decimal
*/
public function pow(Decimal $b, $scale = null)
{
if ($b->isPositive()) {
if ($this->isPositive()) {
return $this;
}
// if ($this->isNegative())
if ($b->isInfinite()) {
throw new \DomainException("Negative infinite elevated to infinite is undefined.");
}
if ($b->isInteger()) {
if (preg_match('/^[+\\-]?[0-9]*[02468](\\.0+)?$/', $b->value, $captures) === 1) {
// $b is an even number
return self::$pInf;
} else {
// $b is an odd number
return $this;
// Negative Infinite
}
}
throw new NotImplementedException("See issues #21, #22, #23 and #24 on Github.");
} else {
if ($b->isNegative()) {
return DecimalConstants::Zero();
} else {
if ($b->isZero()) {
throw new \DomainException("Infinite elevated to zero is undefined.");
}
}
}
}
