Файловый менеджер

Файловый менеджер - Редактировать - C:/xampp/php/PEAR/Math/Numerical/RootFinding/FalsePosition.php

Назад
<?php /* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4 foldmethod=marker: / // {{{ Header /* * Driver file contains Math_Numerical_RootFinding_Bisection class to provide * False Position/Regula Falsi method root finding calculation. * * PHP versions 4 and 5 * * LICENSE: * * BSD License * * Copyright (c) 2004-2006 Firman Wandayandi * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * 3. Neither the name of Firman Wandayandi nor the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * @category Math * @package Math_Numerical_RootFinding * @subpackage Methods * @author Firman Wandayandi <firman@php.net> * @copyright Copyright (c) 2004-2006 Firman Wandayandi * @license http://www.opensource.org/licenses/bsd-license.php * BSD License * @version CVS: $Id: FalsePosition.php,v 1.1 2006/01/30 18:42:00 firman Exp $ / // }}} // {{{ Dependencies /* * Load Math_Numerical_RootFinding_Common as base class. / require_once 'Math/Numerical/RootFinding/Common.php'; // }}} // {{{ Class: Math_Numerical_RootFinding_FalsePosition /* * False Position/Regula Falsi method class. * * @category Math * @package Math_Numerical_RootFinding * @subpackage Methods * @author Firman Wandayandi <firman@php.net> * @copyright Copyright (c) 2004-2006 Firman Wandayandi * @license http://www.opensource.org/licenses/bsd-license.php * BSD License * @version Release: 1.0.0 / class Math_Numerical_RootFinding_FalsePosition extends Math_Numerical_RootFinding_Common { // {{{ Constructor /* * Constructor. * * @param array $options (optional) Options. * * @access public * @see Math_Numerical_RootFinding_Common::Math_Numerical_RootFinding_Common() / function Math_Numerical_RootFinding_FalsePosition($options = null) { parent::Math_Numerical_RootFinding_Common($options); } // }}} // {{{ infoCompute() /* * Print out parameters description for compute() function. * * @access public / function infoCompute() { print "<h2>False Position::compute()</h2>\n" . "<em>float</em> \| <em>PEAR_Error</em> ". "<strong>compute</strong>(<u>\$fxFunction</u>, <u>\$xL</u>, ". "<u>\$xU</u>)<br />\n" . "<h3>Description</h3>\n". "<em>callback</em> <u>\$fxFunction</u> Callback f(x) equation ". "function or object/method tuple.<br>\n" . "<em>float</em> <u>\$xL</u> Lower guess.<br>\n" . "<em>float</em> <u>\$xU</u> Upper guess.<br>\n"; } // }}} // {{{ compute() /* * False Position/Regula Falsi method. * * @param callback $fxFunction Callback f(x) equation function or * object/method tuple. * @param float $xL Lower guess. * @param float $xU Upper guess. * * @return float\|PEAR_Error root value on success or PEAR_Error on failure. * @access public * @see Math_Numerical_RootFinding_Common::validateEqFunction() * @see Math_Numerical_RootFinding_Common::getEqResult() * @see Math_Numerical_RootFinding_Bisection::compute() / function compute($fxFunction, $xL, $xU) { // Validate f(x) equation function. $err = Math_Numerical_RootFinding_Common::validateEqFunction($fxFunction); if (PEAR::isError($err)) { return $err; } // Sets maximum iteration and tolerance from options. $maxIteration = $this->options['max_iteration']; $errTolerance = $this->options['err_tolerance']; // Calculate first approximation $xR (False Position's formula). $fxL = Math_Numerical_RootFinding_Common::getEqResult($fxFunction, $xL); $fxU = Math_Numerical_RootFinding_Common::getEqResult($fxFunction, $xU); if ($fxL - $fxU == 0) { return PEAR::raiseError('Iteration skipped, division by zero'); } $xR = $xU - (($fxU ($xL - $xU)) / ($fxL - $fxU)); // Sets variable for saving errors during iteration, for divergent // detection. $epsErrors = array(); for ($i = 0; $i < $maxIteration; $i++) { // Calculate f(xr), where: xr = $xR $fxR = Math_Numerical_RootFinding_Common::getEqResult($fxFunction, $xR); if ($fxL * $fxR < 0) { // Root is at first subinterval. $xU = $xR; } elseif ($fxL * $fxR > 0) { // Root is at second subinterval. $xL = $xR; } elseif ($fxL * $fxR == 0) { // $xR is the exact root. $this->root = $xR; break; } // Avoid division by zero. if ($fxL - $fxU == 0) { return PEAR::raiseError('Iteration skipped, division by zero'); } // Compute new approximation. $xN = $xU - (($fxU * ($xL - $xU)) / ($fxL - $fxU)); // Compute approximation error. $this->epsError = abs(($xN - $xR) / $xN); $epsErrors[] = $this->epsError; // Detect for divergent rows. if ($this->isDivergentRows($epsErrors) && $this->options['divergent_skip']) { return PEAR::raiseError('Iteration skipped, divergent rows detected'); break; } // Check for error tolerance, if lower than or equal with // $errTolerance it is the root. if ($this->epsError <= $errTolerance) { $this->root = $xN; break; } // Calculate f(xl), where xl = $xL. $fxL = Math_Numerical_RootFinding_Common::getEqResult($fxFunction, $xL); // Calculate f(xu), where xu = $xU. $fxU = Math_Numerical_RootFinding_Common::getEqResult($fxFunction, $xU); // Switch xn -> xr, where xn = $xN and xr = $xR. $xR = $xN; } $this->iterationCount = $i; return $this->root; } // }}} } // }}} /* * Local variables: * mode: php * tab-width: 4 * c-basic-offset: 4 * c-hanging-comment-ender-p: nil * End: */ ?>

| ver. 1.4 | Github | . | PHP 5.3.8 | Генерация страницы: 0.12 | proxy | phpinfo | Настройка