/**
* STDEVP
*
* Calculates standard deviation based on the entire population
*
* Excel Function:
* STDEVP(value1[,value2[, ...]])
*
* @access public
* @category Statistical Functions
* @param mixed $arg,... Data values
* @return float
*/
public static function STDEVP()
{
$aArgs = PHPExcel_Calculation_Functions::flattenArrayIndexed(func_get_args());
// Return value
$returnValue = null;
$aMean = self::AVERAGE($aArgs);
if (!is_null($aMean)) {
$aCount = 0;
foreach ($aArgs as $k => $arg) {
if (is_bool($arg) && (!PHPExcel_Calculation_Functions::isCellValue($k) || PHPExcel_Calculation_Functions::getCompatibilityMode() == PHPExcel_Calculation_Functions::COMPATIBILITY_OPENOFFICE)) {
$arg = (int) $arg;
}
// Is it a numeric value?
if (is_numeric($arg) && !is_string($arg)) {
if (is_null($returnValue)) {
$returnValue = pow($arg - $aMean, 2);
} else {
$returnValue += pow($arg - $aMean, 2);
}
++$aCount;
}
}
// Return
if ($aCount > 0 && $returnValue >= 0) {
return sqrt($returnValue / $aCount);
}
}
return PHPExcel_Calculation_Functions::DIV0();
}
