/**
* Returns key of the input array based on the "powers" of array values.
*
* @param array $powers Array of non-negative float values.
* Each key's "power" means likeness of this key
* being returned.
*
* @return mixed A key of the input array.
*
* @throws InvalidArgumentException for empty input or invalid power values.
*/
public function getArrayKeyByPowers(array $powers)
{
if (empty($powers)) {
throw new InvalidArgumentException('Empty powers set');
}
$powersSum = 0;
foreach ($powers as $power) {
if ($power < 0) {
throw new InvalidArgumentException('Negative power found');
}
$powersSum += $power;
}
if ($powersSum <= 0) {
throw new InvalidArgumentException('The sum of powers must be positive');
}
$randomValue = $this->generator->getFloat(0, $powersSum);
$currentSum = 0;
$result = null;
foreach ($powers as $key => $power) {
$currentSum += $power;
if ($currentSum >= $randomValue) {
$result = $key;
break;
}
}
return $key;
}
/**
* @expectedException InvalidArgumentException
*/
public function testIfGetFloatThrowsExceptions()
{
$this->generator->getFloat(5.0002, 5.0001);
}
