PHPExcel_Shared_Best_Fit

# Source for file logarithmicBestFitClass.php Documentation is available at logarithmicBestFitClass.php <?php /** * PHPExcel * * Copyright (c) 2006 - 2010 PHPExcel * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * @category PHPExcel * @package PHPExcel_Shared_Best_Fit * @copyright Copyright (c) 2006 - 2010 PHPExcel (http://www.codeplex.com/PHPExcel) * @license http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt LGPL * @version 1.7.2, 2010-01-11 */ /** PHPExcel root directory */ if (!defined('PHPEXCEL_ROOT')) { /** * @ignore */ define('PHPEXCEL_ROOT', dirname(__FILE__) . '/../../../'); } require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php'); /** * PHPExcel_Logarithmic_Best_Fit * * @category PHPExcel * @package PHPExcel_Shared_Best_Fit * @copyright Copyright (c) 2006 - 2010 PHPExcel (http://www.codeplex.com/PHPExcel) */ class PHPExcel_Logarithmic_Best_Fit extends PHPExcel_Best_Fit { protected $_bestFitType = 'logarithmic'; public function getValueOfYForX($xValue) { return $this->getIntersect() + $this->getSlope() * log($xValue - $this->_Xoffset); } // function getValueOfYForX() public function getValueOfXForY($yValue) { return exp(($yValue - $this->getIntersect()) / $this->getSlope()); } // function getValueOfXForY() public function getEquation($dp=0) { $slope = $this->getSlope($dp); $intersect = $this->getIntersect($dp); return 'Y = '.$intersect.' + '.$slope.' * log(X)'; } // function getEquation() private function _logarithmic_regression($yValues, $xValues, $const) { foreach($xValues as &$value) { if ($value < 0.0) { $value = 0 - log(abs($value)); } elseif ($value > 0.0) { $value = log($value); } } unset($value); $this->_leastSquareFit($yValues, $xValues, $const); } // function _logarithmic_regression() function __construct($yValues, $xValues=array(), $const=True) { if (parent::__construct($yValues, $xValues) !== False) { $this->_logarithmic_regression($yValues, $xValues, $const); } } // function __construct() } // class logarithmicBestFit Documentation generated on Mon, 11 Jan 2010 08:11:56 +0100 by phpDocumentor 1.4.1