DStDevP.php
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<?php
namespace PhpOffice\PhpSpreadsheet\Calculation\Database;
use PhpOffice\PhpSpreadsheet\Calculation\Statistical\StandardDeviations;
class DStDevP extends DatabaseAbstract
{
/**
* DSTDEVP.
*
* Calculates the standard deviation of a population based on the entire population by using the
* numbers in a column of a list or database that match conditions that you specify.
*
* Excel Function:
* DSTDEVP(database,field,criteria)
*
* @param mixed[] $database The range of cells that makes up the list or database.
* A database is a list of related data in which rows of related
* information are records, and columns of data are fields. The
* first row of the list contains labels for each column.
* @param int|string $field Indicates which column is used in the function. Enter the
* column label enclosed between double quotation marks, such as
* "Age" or "Yield," or a number (without quotation marks) that
* represents the position of the column within the list: 1 for
* the first column, 2 for the second column, and so on.
* @param mixed[] $criteria The range of cells that contains the conditions you specify.
* You can use any range for the criteria argument, as long as it
* includes at least one column label and at least one cell below
* the column label in which you specify a condition for the
* column.
*
* @return null|float|string
*/
public static function evaluate($database, $field, $criteria)
{
$field = self::fieldExtract($database, $field);
if ($field === null) {
return null;
}
return StandardDeviations::STDEVP(
self::getFilteredColumn($database, $field, $criteria)
);
}
}