Line data    Source code

       1             : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       2             :    Copyright (c) 2016-2023 The plumed team
       3             :    (see the PEOPLE file at the root of the distribution for a list of names)
       4             : 
       5             :    See http://www.plumed.org for more information.
       6             : 
       7             :    This file is part of plumed, version 2.
       8             : 
       9             :    plumed is free software: you can redistribute it and/or modify
      10             :    it under the terms of the GNU Lesser General Public License as published by
      11             :    the Free Software Foundation, either version 3 of the License, or
      12             :    (at your option) any later version.
      13             : 
      14             :    plumed is distributed in the hope that it will be useful,
      15             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      16             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      17             :    GNU Lesser General Public License for more details.
      18             : 
      19             :    You should have received a copy of the GNU Lesser General Public License
      20             :    along with plumed.  If not, see <http://www.gnu.org/licenses/>.
      21             : +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
      22             : #ifndef __PLUMED_tools_RootFindingBase_h
      23             : #define __PLUMED_tools_RootFindingBase_h
      24             : 
      25             : #include "MinimiseBase.h"
      26             : #include "Brent1DRootSearch.h"
      27             : 
      28             : namespace PLMD {
      29             : 
      30             : template <class FCLASS>
      31             : class RootFindingBase {
      32             : private:
      33             : /// This is the pointer to the member function in the energy
      34             : /// calculating class that calculates the energy
      35             :   typedef double(FCLASS::*engf_pointer)( const std::vector<double>& p, std::vector<double>& der ) const ;
      36             :   typedef double(FCLASS::*engfnc_pointer)( const std::vector<double>& p, std::vector<double>& der ) ;
      37             : /// The class that calculates the energy given a position
      38             :   FCLASS* myclass_func;
      39             : /// This actually does the search for a root
      40             :   void doSearch( const std::vector<double>& dir, std::vector<double>& p, F1dim<FCLASS>& f1dim  ) const ;
      41             : public:
      42           6 :   explicit RootFindingBase( FCLASS* funcc ) : myclass_func(funcc) {}
      43             : /// This is the line minimiser
      44             :   void linesearch( const std::vector<double>& dir, std::vector<double>& p, engf_pointer myfunc ) const ;
      45             :   void lsearch( const std::vector<double>& dir, std::vector<double>& p, engfnc_pointer myfunc ) const ;
      46             : };
      47             : 
      48             : template <class FCLASS>
      49        2187 : void RootFindingBase<FCLASS>::doSearch( const std::vector<double>& dir, std::vector<double>& p, F1dim<FCLASS>& f1dim ) const {
      50             :   // Construct an object that will do the line search for the minimum
      51        2187 :   Brent1DRootSearch<F1dim<FCLASS> > bb(f1dim);
      52             : 
      53             :   // This does the actual search for the root
      54        2187 :   double ax=0.0, xx=1.0;
      55        2187 :   bb.bracket( ax, xx, &F1dim<FCLASS>::getEng );
      56        2187 :   double xmin=bb.search( &F1dim<FCLASS>::getEng );
      57        8748 :   for(unsigned i=0; i<p.size(); ++i) p[i] += xmin*dir[i];
      58        2187 : }
      59             : 
      60             : template <class FCLASS>
      61        1896 : void RootFindingBase<FCLASS>::linesearch( const std::vector<double>& dir, std::vector<double>& p, engf_pointer myfunc ) const {
      62             :   // Construct the object that turns points on a line into vectors
      63        1896 :   F1dim<FCLASS> f1dim( p, dir, myclass_func, myfunc, NULL );
      64             :   // Actually do the search
      65        1896 :   doSearch( dir, p, f1dim );
      66        1896 : }
      67             : 
      68             : template <class FCLASS>
      69         291 : void RootFindingBase<FCLASS>::lsearch( const std::vector<double>& dir, std::vector<double>& p, engfnc_pointer myfunc ) const {
      70             :   // Construct the object that turns points on a line into vectors
      71         291 :   F1dim<FCLASS> f1dim( p, dir, myclass_func, NULL, myfunc );
      72             :   // Actually do the search
      73         291 :   doSearch( dir, p, f1dim );
      74         291 : }
      75             : 
      76             : }
      77             : #endif