Line data    Source code

       1             : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       2             :    Copyright (c) 2012-2017 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             : #include "RDF.h"
      23             : #include "core/ActionRegister.h"
      24             : #include "core/ActionShortcut.h"
      25             : 
      26             : //+PLUMEDOC MCOLVAR PAIRENTROPY
      27             : /*
      28             : Calculate the KL Entropy from the radial distribution function
      29             : 
      30             : \par Examples
      31             : 
      32             : */
      33             : //+ENDPLUMEDOC
      34             : 
      35             : namespace PLMD {
      36             : namespace gridtools {
      37             : 
      38             : class PairEntropy : public ActionShortcut {
      39             : public:
      40             :   static void registerKeywords( Keywords& keys );
      41             :   explicit PairEntropy(const ActionOptions&ao);
      42             : };
      43             : 
      44             : PLUMED_REGISTER_ACTION(PairEntropy,"PAIRENTROPY")
      45             : 
      46         131 : void PairEntropy::registerKeywords( Keywords& keys ) {
      47         131 :   RDF::registerKeywords( keys ); keys.needsAction("RDF");
      48         262 :   keys.setValueDescription("scalar","the KL-entropy that is computed from the radial distribution function");
      49         262 :   keys.needsAction("INTERPOLATE_GRID"); keys.needsAction("INTEGRATE_GRID");
      50         131 : }
      51             : 
      52          65 : PairEntropy::PairEntropy(const ActionOptions&ao):
      53             :   Action(ao),
      54          65 :   ActionShortcut(ao)
      55             : {
      56         130 :   std::string ref_str, ref_name; parse("REFERENCE",ref_name);
      57         130 :   if( ref_name.length()>0 ) ref_str = "REFERENCE=" + ref_name; else ref_name = getShortcutLabel() + "_rdf";
      58             :   // Read in the atoms and get the number of atoms that we are using
      59         130 :   std::string atom_str, group_str, natoms; parse("GROUP",group_str);
      60          65 :   if( group_str.length()>0 ) {
      61           1 :     atom_str="GROUP=" + group_str;
      62           1 :     std::vector<std::string> awords=Tools::getWords(group_str,"\t\n ,");
      63           1 :     Tools::interpretRanges( awords ); Tools::convert( awords.size(), natoms );
      64           1 :   } else {
      65             :     std::string groupa_str, groupb_str;
      66         128 :     parse("GROUPA",groupa_str); parse("GROUPB",groupb_str);
      67         128 :     atom_str="GROUPA=" + groupa_str + " GROUPB=" + groupb_str;
      68          64 :     std::vector<std::string> awords=Tools::getWords(groupb_str,"\t\n ,");
      69          64 :     Tools::interpretRanges( awords ); Tools::convert( awords.size()+1, natoms );
      70          64 :   }
      71             :   // Read in all other keywords and create the RDF object
      72         390 :   std::string maxr, nbins, dens, bw, cutoff; parse("MAXR",maxr); parse("GRID_BIN",nbins); parse("DENSITY",dens); parse("BANDWIDTH",bw); parse("CUTOFF",cutoff);
      73          65 :   std::string dens_str; if( dens.length()>0 ) dens_str = " DENSITY=" + dens;
      74         130 :   readInputLine( getShortcutLabel() + "_rdf: RDF " + atom_str + " CUTOFF=" + cutoff + " GRID_BIN=" + nbins + " MAXR=" + maxr + dens_str + " BANDWIDTH=" + bw + " " + ref_str);
      75             :   // And compute the two functions we are integrating (we use two matheval objects here and sum them in order to avoid nans from taking logarithms of zero)
      76         130 :   readInputLine( getShortcutLabel() + "_conv_t1: CUSTOM ARG=" + getShortcutLabel() + "_rdf," + ref_name + "_x2 FUNC=x*y*log(x) PERIODIC=NO");
      77         130 :   readInputLine( getShortcutLabel() + "_conv_t2: CUSTOM ARG=" + getShortcutLabel() + "_rdf," + ref_name + "_x2 FUNC=(1-x)*y PERIODIC=NO");
      78         130 :   readInputLine( getShortcutLabel() + "_conv: CUSTOM ARG=" + getShortcutLabel() + "_conv_t1," + getShortcutLabel() + "_conv_t2 FUNC=x+y PERIODIC=NO");
      79             :   // Now integrate using trapezium rule
      80         130 :   readInputLine( getShortcutLabel() + "_midp: INTERPOLATE_GRID ARG=" + getShortcutLabel() + "_conv INTERPOLATION_TYPE=linear MIDPOINTS"); // First interpolate onto midpoints
      81         130 :   readInputLine( getShortcutLabel() + "_int: INTEGRATE_GRID ARG=" + getShortcutLabel() + "_midp PERIODIC=NO"); // And then integrate
      82             :   // And multiply by final normalizing constant
      83             :   std::string norm_str;
      84          65 :   if( dens.length()>0 ) norm_str = " FUNC=-2*pi*x*" + dens;
      85         130 :   else norm_str = "," + ref_name + "_vol FUNC=-(2*pi*x/y)*" + natoms;
      86         130 :   readInputLine( getShortcutLabel() + ": CUSTOM PERIODIC=NO ARG=" + getShortcutLabel() + "_int" + norm_str );
      87          65 : }
      88             : 
      89             : }
      90             : }