Line data Source code
1 : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 : Copyright (c) 2015-2019 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_MinimiseBase_h
23 : #define __PLUMED_tools_MinimiseBase_h
24 :
25 : #include "Minimise1DBrent.h"
26 :
27 : namespace PLMD {
28 :
29 : template <class FCLASS>
30 7580 : class F1dim {
31 : private:
32 : /// This is the pointer to the member funciton in the energy
33 : /// calculating class that calculates the energy
34 : typedef double(FCLASS::*engf_pointer)( const std::vector<double>& p, std::vector<double>& der ) const ;
35 : typedef double(FCLASS::*engfnc_pointer)( const std::vector<double>& p, std::vector<double>& der ) ;
36 : /// Pointer to the vector containing an initial position on the vector
37 : const std::vector<double>& p;
38 : /// The direction of the vector we are minimising along
39 : const std::vector<double>& dir;
40 : /// Tempory vector that holds a point at which we want to calculate the energy
41 : std::vector<double> pt;
42 : /// Vector that holds the derivatives at the point at which we calculate the energy (these are not used)
43 : std::vector<double> fake_der;
44 : /// Class containging the function in the class
45 : FCLASS* func;
46 : /// Member of class that calculates the energy we are trying to mnimise
47 : engf_pointer calc;
48 : /// Member of class that calcualtes the energy we are trying to minimise
49 : engfnc_pointer calc2;
50 : public:
51 : explicit F1dim( const std::vector<double>& pp, const std::vector<double>& dd, FCLASS* ff, engf_pointer cc, engfnc_pointer cc2 );
52 : /// Calculate the energy at \f$\mathbf{p} + xt*\mathbf{dir}\f$
53 : double getEng( const double& xt );
54 : };
55 :
56 : template <class FCLASS>
57 1516 : F1dim<FCLASS>::F1dim( const std::vector<double>& pp, const std::vector<double>& dd, FCLASS* ff, engf_pointer cc, engfnc_pointer cc2 ):
58 : p(pp),
59 : dir(dd),
60 : pt(pp.size()),
61 : fake_der(pp.size()),
62 : func(ff),
63 : calc(cc),
64 4548 : calc2(cc2)
65 : {
66 1516 : plumed_assert( calc || calc2 );
67 1516 : }
68 :
69 : template <class FCLASS>
70 10446 : double F1dim<FCLASS>::getEng( const double& xt ) {
71 177582 : for(unsigned j=0; j<pt.size(); ++j) pt[j] = p[j] + xt*dir[j];
72 10446 : if( calc ) return (func->*calc)(pt,fake_der);
73 2200 : return (func->*calc2)(pt,fake_der);
74 : }
75 :
76 : template <class FCLASS>
77 : class MinimiseBase {
78 : private:
79 : /// This is the pointer to the member funciton in the energy
80 : /// calculating class that calculates the energy
81 : typedef double(FCLASS::*engf_pointer)( const std::vector<double>& p, std::vector<double>& der );
82 : /// The class that calculates the energy given a position
83 : FCLASS* myclass_func;
84 : protected:
85 : /// This calculates the derivatives at a point
86 : double calcDerivatives( const std::vector<double>& p, std::vector<double>& der, engf_pointer myfunc );
87 : public:
88 : explicit MinimiseBase( FCLASS* funcc ) : myclass_func(funcc) {}
89 : /// This is the line minimiser
90 : double linemin( const std::vector<double>& dir, std::vector<double>& p, engf_pointer myfunc );
91 : };
92 :
93 : template <class FCLASS>
94 : double MinimiseBase<FCLASS>::linemin( const std::vector<double>& dir, std::vector<double>& p, engf_pointer myfunc ) {
95 : // Construct the object that turns points on a line into vectors
96 : F1dim<FCLASS> f1dim( p, dir, myclass_func, NULL, myfunc );
97 :
98 : // Construct an object that will do the line search for the minimum
99 : Minimise1DBrent<F1dim<FCLASS> > bb(f1dim);
100 :
101 : // This does the actual line minimisation
102 : double ax=0.0, xx=1.0;
103 : bb.bracket( ax, xx, &F1dim<FCLASS>::getEng );
104 : double xmin=bb.minimise( &F1dim<FCLASS>::getEng );
105 : for(unsigned i=0; i<p.size(); ++i) p[i] += xmin*dir[i];
106 : return bb.getMinimumValue();
107 : }
108 :
109 : template <class FCLASS>
110 : double MinimiseBase<FCLASS>::calcDerivatives( const std::vector<double>& p, std::vector<double>& der, engf_pointer myfunc ) {
111 :
112 : return (myclass_func->*myfunc)( p, der );
113 : }
114 :
115 : }
116 : #endif
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