.. _program_listing_file_rootFinding_NewtonRootFinder_NewtonRootFinder.C:

Program Listing for File NewtonRootFinder.C
===========================================

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

.. |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/>.
   
   \*---------------------------------------------------------------------------*/
   
   #include "NewtonRootFinder.H"
   #include "addToRunTimeSelectionTable.H"
   
   using namespace boost::math::policies;
   
   // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
   
   #if !defined(DOXYGEN_SHOULD_SKIP_THIS)
   namespace Foam
   {
       defineTypeNameAndDebug(NewtonRootFinder, 0);
       addToRunTimeSelectionTable(RootFinder, NewtonRootFinder, Word);
       addToRunTimeSelectionTable(RootFinder, NewtonRootFinder, Dictionary);
       addToRunTimeSelectionTable(RootFinder, NewtonRootFinder, DictionaryOnly);
   }
   #endif
   
   typedef policy<
         domain_error<ignore_error>,
         overflow_error<ignore_error>
         > myPolicy;
   
   // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
   
   std::pair<Foam::scalar, Foam::label> Foam::NewtonRootFinder::root(
       scalar guess,
       scalar lowerBound,
       scalar upperBound
   ) const
   {
   
       label iterations = 0;
       auto funcTuple = [this, &iterations](scalar uTau)
       {
           iterations++;
           return std::make_pair(this->f_(uTau), this->d_(uTau));
       };
   
       auto maxIter = static_cast<boost::uintmax_t>(maxIter_);
   
       scalar result = boost::math::tools::newton_raphson_iterate(
           funcTuple,
           guess,
           lowerBound,
           upperBound,
           getDigits_,
           maxIter
       );
   
       return std::make_pair(result, iterations);
   }
   
   // ************************************************************************* //