.. _program_listing_file_rootFinding_NewtonRootFinder_NewtonRootFinder.H:

Program Listing for File NewtonRootFinder.H
===========================================

|exhale_lsh| :ref:`Return to documentation for file <file_rootFinding_NewtonRootFinder_NewtonRootFinder.H>` (``rootFinding/NewtonRootFinder/NewtonRootFinder.H``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /*---------------------------------------------------------------------------* \
   License
       This file is part of libWallModelledLES.
   
       libWallModelledLES is free software: you can redistribute it and/or modify
       it under the terms of the GNU General Public License as published by
       the Free Software Foundation, either version 3 of the License, or
       (at your option) any later version.
   
       libWallModelledLES 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 General Public License
       for more details.
   
       You should have received a copy of the GNU General Public License
       along with libWallModelledLES.
       If not, see <http://www.gnu.org/licenses/>.
   
   Class
       Foam::NewtonRootFinder
   
   @brief
       Root finder based on Newton's method.
   
       Controlled by the maximum number of iterations. The convergence tolerance is
       fixed internally as a binary digit target for the root estimate.
   
       Usage
       \verbatim
       RootFinder
       {
           type       Newton;
           maxIter    value; (default 30)
       }
       \endverbatim
   
   Contributors/Copyright:
       2016-2026 Timofey Mukha
       2017      Saleh Rezaeiravesh
   
   SourceFiles
       NewtonRootFinder.C
   
   \*---------------------------------------------------------------------------*/
   
   #ifndef NewtonRootFinder_H
   #define NewtonRootFinder_H
   
   #include "RootFinder.H"
   
   // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
   
   namespace Foam
   {
   
   /*---------------------------------------------------------------------------*\
                         Class NewtonRoot Declaration
   \*---------------------------------------------------------------------------*/
   
   class NewtonRootFinder : public RootFinder
   {
   private:
       //- Number of binary digits requested in the solution
       label getDigits_ =
           static_cast<int>(std::numeric_limits<scalar>::digits * 0.4);
   
   public:
   
   #if !defined(DOXYGEN_SHOULD_SKIP_THIS)
       TypeName("Newton");
   #endif
   
       // Constructors
   
           //- Construct given name, function, its derivative and maximum number
           //  of iterations
           NewtonRootFinder
           (
               const word & rootFinderName,
               std::function<scalar(scalar)> f,
               std::function<scalar(scalar)> d,
               const label maxIter
           )
           :
           RootFinder(rootFinderName, f, d, maxIter)
           {}
   
           //- Construct given a function, its derivative, and dictionary
           NewtonRootFinder
           (
               std::function<scalar(scalar)> f,
               std::function<scalar(scalar)> d,
               const dictionary & dict
           )
           :
           RootFinder(f, d, dict)
           {
           }
   
   
           //- Construct given  dictionary
           NewtonRootFinder
           (
               const dictionary & dict
           )
           :
           RootFinder(dict)
           {}
   
           //- Copy constructor
           NewtonRootFinder(const NewtonRootFinder &) = default;
   
           //- Clone the object
           virtual autoPtr<RootFinder> clone() const
           {
               return autoPtr<RootFinder>
               (
                   new NewtonRootFinder(*this)
               );
           }
   
   
       //- Destructor
           virtual ~NewtonRootFinder(){};
   
       // Member Functions
   
           //- Compute and return root
           std::pair<scalar, label> root
           (
               scalar guess,
               scalar lowerBound,
               scalar upperBound
           ) const;
   
           //- Write
           virtual void write(Ostream& os) const
           {
               RootFinder::write(os);
               os << decrIndent;
               os.writeKeyword("}") << endl;
           }
   
   };
   
   
   
   
   // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
   
   } // End namespace Foam
   
   // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
   
   #endif