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# Source for file trendClass.php Documentation is available at trendClass.php <?php /** PHPExcel root directory */ if (!defined('PHPEXCEL_ROOT')) { /** * @ignore */ define('PHPEXCEL_ROOT', dirname(__FILE__) . '/../../../'); } require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/linearBestFitClass.php'; require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/logarithmicBestFitClass.php'; require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/exponentialBestFitClass.php'; require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/powerBestFitClass.php'; require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/polynomialBestFitClass.php'; class trendClass { const TREND_LINEAR = 'Linear'; const TREND_LOGARITHMIC = 'Logarithmic'; const TREND_EXPONENTIAL = 'Exponential'; const TREND_POWER = 'Power'; const TREND_POLYNOMIAL_2 = 'Polynomial_2'; const TREND_POLYNOMIAL_3 = 'Polynomial_3'; const TREND_POLYNOMIAL_4 = 'Polynomial_4'; const TREND_POLYNOMIAL_5 = 'Polynomial_5'; const TREND_POLYNOMIAL_6 = 'Polynomial_6'; const TREND_BEST_FIT = 'Bestfit'; const TREND_BEST_FIT_NO_POLY = 'Bestfit_no_Polynomials'; private static $_trendTypes = array( self::TREND_LINEAR, self::TREND_LOGARITHMIC, self::TREND_EXPONENTIAL, self::TREND_POWER ); private static $_trendTypePolyOrders = array( self::TREND_POLYNOMIAL_2, self::TREND_POLYNOMIAL_3, self::TREND_POLYNOMIAL_4, self::TREND_POLYNOMIAL_5, self::TREND_POLYNOMIAL_6 ); private static $_trendCache = array(); public static function calculate($trendType=self::TREND_BEST_FIT, $yValues, $xValues=array(), $const=True) { // Calculate number of points in each dataset $nY = count($yValues); $nX = count($xValues); // Define X Values if necessary if ($nX == 0) { $xValues = range(1,$nY); $nX = $nY; } elseif ($nY != $nX) { // Ensure both arrays of points are the same size trigger_error("trend(): Number of elements in coordinate arrays do not match.", E_USER_ERROR); } $key = md5($trendType.$const.serialize($yValues).serialize($xValues)); // Determine which trend method has been requested switch ($trendType) { // Instantiate and return the class for the requested trend method case self::TREND_LINEAR : case self::TREND_LOGARITHMIC : case self::TREND_EXPONENTIAL : case self::TREND_POWER : if (!isset(self::$_trendCache[$key])) { $className = 'PHPExcel_'.$trendType.'_Best_Fit'; self::$_trendCache[$key] = new $className($yValues,$xValues,$const); } return self::$_trendCache[$key]; break; case self::TREND_POLYNOMIAL_2 : case self::TREND_POLYNOMIAL_3 : case self::TREND_POLYNOMIAL_4 : case self::TREND_POLYNOMIAL_5 : case self::TREND_POLYNOMIAL_6 : if (!isset(self::$_trendCache[$key])) { $order = substr($trendType,-1); self::$_trendCache[$key] = new PHPExcel_Polynomial_Best_Fit($order,$yValues,$xValues,$const); } return self::$_trendCache[$key]; break; case self::TREND_BEST_FIT : case self::TREND_BEST_FIT_NO_POLY : // If the request is to determine the best fit regression, then we test each trend line in turn // Start by generating an instance of each available trend method foreach(self::$_trendTypes as $trendMethod) { $className = 'PHPExcel_'.$trendMethod.'BestFit'; $bestFit[$trendMethod] = new $className($yValues,$xValues,$const); $bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit(); } if ($trendType != self::TREND_BEST_FIT_NO_POLY) { foreach(self::$_trendTypePolyOrders as $trendMethod) { $order = substr($trendMethod,-1); $bestFit[$trendMethod] = new PHPExcel_Polynomial_Best_Fit($order,$yValues,$xValues,$const); if ($bestFit[$trendMethod]->getError()) { unset($bestFit[$trendMethod]); } else { $bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit(); } } } // Determine which of our trend lines is the best fit, and then we return the instance of that trend class arsort($bestFitValue); $bestFitType = key($bestFitValue); return $bestFit[$bestFitType]; break; default : return false; } } // function calculate() } // class trendClass Documentation generated on Mon, 11 Jan 2010 08:16:00 +0100 by phpDocumentor 1.4.1