// If you don't have the php_stats library, you can use this function:public static function getKurtosis( $values ){ $numValues = count( $values ); if ( $numValues == 0 ) { return 0.0; } // Use function from php_stats library if available if ( function_exists( 'stats_kurtosis' ) ) { return stats_kurtosis( $values ); } $mean = array_sum( $values ) / floatval( $numValues ); $add2 = 0.0; $add4 = 0.0; foreach ( $values as $value ) { if ( ! is_numeric( $value ) ) { return false; } $dif = $value - $mean; $dif2 = $dif * $dif; $add2 += $dif2; $add4 += ( $dif2 * $dif2 ); } // foreach values $variance = $add2 / floatval( $numValues ); return ( $add4 * $numValues ) / ( $add2 * $add2 ) - 3.0;}