/** * GEOMEAN * * Returns the geometric mean of an array or range of positive data. For example, you * can use GEOMEAN to calculate average growth rate given compound interest with * variable rates. * * Excel Function: * GEOMEAN(value1[,value2[, ...]]) * * @access public * @category Statistical Functions * @param mixed $arg,... Data values * @return float */ public static function GEOMEAN() { $aArgs = Functions::flattenArray(func_get_args()); $aMean = MathTrig::PRODUCT($aArgs); if (is_numeric($aMean) && $aMean > 0) { $aCount = self::COUNT($aArgs); if (self::MIN($aArgs) > 0) { return pow($aMean, 1 / $aCount); } } return Functions::NAN(); }
/** * DPRODUCT * * Multiplies the values in a column of a list or database that match conditions that you specify. * * Excel Function: * DPRODUCT(database,field,criteria) * * @access public * @category Database Functions * @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 string|integer $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[] $criteria The range of cells that contains the conditions you specify. * You can use any range for the criteria argument, as long as it * includes at least one column label and at least one cell below * the column label in which you specify a condition for the * column. * @return float * */ public static function DPRODUCT($database, $field, $criteria) { $field = self::fieldExtract($database, $field); if (is_null($field)) { return null; } // Return return MathTrig::PRODUCT(self::getFilteredColumn($database, $field, $criteria)); }