Combinations.php
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<?php
namespace PhpOffice\PhpSpreadsheet\Calculation\MathTrig;
use PhpOffice\PhpSpreadsheet\Calculation\Exception;
class Combinations
{
/**
* COMBIN.
*
* Returns the number of combinations for a given number of items. Use COMBIN to
* determine the total possible number of groups for a given number of items.
*
* Excel Function:
* COMBIN(numObjs,numInSet)
*
* @param mixed $numObjs Number of different objects
* @param mixed $numInSet Number of objects in each combination
*
* @return float|int|string Number of combinations, or a string containing an error
*/
public static function withoutRepetition($numObjs, $numInSet)
{
try {
$numObjs = Helpers::validateNumericNullSubstitution($numObjs, null);
$numInSet = Helpers::validateNumericNullSubstitution($numInSet, null);
Helpers::validateNotNegative($numInSet);
Helpers::validateNotNegative($numObjs - $numInSet);
} catch (Exception $e) {
return $e->getMessage();
}
return round(Factorial::fact($numObjs) / Factorial::fact($numObjs - $numInSet)) / Factorial::fact($numInSet);
}
/**
* COMBIN.
*
* Returns the number of combinations for a given number of items. Use COMBIN to
* determine the total possible number of groups for a given number of items.
*
* Excel Function:
* COMBIN(numObjs,numInSet)
*
* @param mixed $numObjs Number of different objects
* @param mixed $numInSet Number of objects in each combination
*
* @return float|int|string Number of combinations, or a string containing an error
*/
public static function withRepetition($numObjs, $numInSet)
{
try {
$numObjs = Helpers::validateNumericNullSubstitution($numObjs, null);
$numInSet = Helpers::validateNumericNullSubstitution($numInSet, null);
Helpers::validateNotNegative($numInSet);
Helpers::validateNotNegative($numObjs);
$numObjs = (int) $numObjs;
$numInSet = (int) $numInSet;
// Microsoft documentation says following is true, but Excel
// does not enforce this restriction.
//Helpers::validateNotNegative($numObjs - $numInSet);
if ($numObjs === 0) {
Helpers::validateNotNegative(-$numInSet);
return 1;
}
} catch (Exception $e) {
return $e->getMessage();
}
return round(Factorial::fact($numObjs + $numInSet - 1) / Factorial::fact($numObjs - 1)) / Factorial::fact($numInSet);
}
}