root/Math/GSLRootFinder.h

0001 // @(#)root/mathmore:$Id$
0002 // Author: L. Moneta, A. Zsenei   08/2005
0003
0004  /**********************************************************************
0005   *                                                                    *
0006   * Copyright (c) 2004 ROOT Foundation,  CERN/PH-SFT                   *
0007   *                                                                    *
0008   * This library is free software; you can redistribute it and/or      *
0009   * modify it under the terms of the GNU General Public License        *
0010   * as published by the Free Software Foundation; either version 2     *
0011   * of the License, or (at your option) any later version.             *
0012   *                                                                    *
0013   * This library is distributed in the hope that it will be useful,    *
0014   * but WITHOUT ANY WARRANTY; without even the implied warranty of     *
0015   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU   *
0016   * General Public License for more details.                           *
0017   *                                                                    *
0018   * You should have received a copy of the GNU General Public License  *
0019   * along with this library (see file COPYING); if not, write          *
0020   * to the Free Software Foundation, Inc., 59 Temple Place, Suite      *
0021   * 330, Boston, MA 02111-1307 USA, or contact the author.             *
0022   *                                                                    *
0023   **********************************************************************/
0024
0025 // Header file for class GSLRootFinder
0026 //
0027 // Created by: moneta  at Sun Nov 14 11:27:11 2004
0028 //
0029 // Last update: Sun Nov 14 11:27:11 2004
0030 //
0031 #ifndef ROOT_Math_GSLRootFinder
0032 #define ROOT_Math_GSLRootFinder
0033
0034
0035 #include "Math/GSLFunctionAdapter.h"
0036
0037 #include "Math/IFunctionfwd.h"
0038
0039 #include "Math/IRootFinderMethod.h"
0040
0041 #include <iostream>
0042
0043 namespace ROOT {
0044 namespace Math {
0045
0046
0047    class GSLRootFSolver;
0048    class GSLFunctionWrapper;
0049
0050
0051 //________________________________________________________________________________________________________
0052   /**
0053      Base class for GSL Root-Finding algorithms for one dimensional functions which do not use function derivatives.
0054      For finding the roots users should not use this class directly but instantiate the derived classes,
0055      for example  ROOT::Math::Roots::Brent for using the Brent algorithm.
0056      All the classes defining the alhorithms are defined in the header Math/RootFinderAlgorithm.h
0057      They possible types implementing root bracketing algorithms which they do not require function
0058      derivatives are:
0059      <ul>
0060          <li>ROOT::Math::Roots::Bisection
0061          <li>ROOT::Math::Roots::FalsePos
0062          <li>ROOT::Math::Roots::Brent
0063      </ul>
0064
0065      See also the specific  classes for the documentation.
0066      See the GSL <A HREF="http://www.gnu.org/software/gsl/manual/html_node/Root-Bracketing-Algorithms.html"> online manual</A> for
0067      information on the GSL Root-Finding algorithms
0068
0069      @ingroup RootFinders
0070   */
0071
0072
0073  class GSLRootFinder: public IRootFinderMethod {
0074
0075  public:
0076     GSLRootFinder();
0077     ~GSLRootFinder() override;
0078
0079     // usually copying is non trivial, so we delete this
0080     GSLRootFinder(const GSLRootFinder &) = delete;
0081     GSLRootFinder &operator=(const GSLRootFinder &) = delete;
0082     GSLRootFinder(GSLRootFinder &&) = delete;
0083     GSLRootFinder &operator=(GSLRootFinder &&) = delete;
0084
0085 #if defined(__MAKECINT__) || defined(G__DICTIONARY)
0086     bool SetFunction( const IGradFunction & , double ) override {
0087        std::cerr <<"GSLRootFinder - Error : this method must be used with a Root Finder algorithm using derivatives" << std::endl;
0088        return false;
0089     }
0090 #endif
0091
0092     bool SetFunction( const IGenFunction & f, double xlow, double xup) override;
0093
0094     typedef double ( * GSLFuncPointer ) ( double, void *);
0095     bool SetFunction( GSLFuncPointer  f, void * params, double xlow, double xup);
0096
0097     using IRootFinderMethod::SetFunction;
0098
0099     // iterate to find ROOTS return GSL_CONTINUE if iteration was successful or another error
0100     int Iterate() override;
0101
0102     double Root() const override;
0103
0104     //double XLower() const;
0105
0106     //double XUpper() const;
0107
0108     /// Find the root
0109     bool Solve( int maxIter = 100, double absTol = 1E-8, double relTol = 1E-10) override;
0110
0111     /// Return number of iterations
0112     int Iterations() const override {
0113        return fIter;
0114     }
0115
0116     /// Return the status of last root finding
0117     int Status() const override { return fStatus; }
0118
0119     const char * Name() const override;
0120
0121
0122  protected:
0123
0124
0125     void SetSolver (  GSLRootFSolver * s );
0126
0127     void FreeSolver();
0128
0129  private:
0130
0131     GSLFunctionWrapper * fFunction;
0132     GSLRootFSolver * fS;
0133
0134     double fRoot;
0135     double fXlow;
0136     double fXup;
0137     int fIter;
0138     int fStatus;
0139     bool fValidInterval;
0140
0141  };
0142
0143 } // namespace Math
0144 } // namespace ROOT
0145
0146
0147 #endif /* ROOT_Math_GSLRootFinder */