Line data    Source code

       1             : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       2             :    Copyright (c) 2011-2017 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             : #ifndef __PLUMED_function_LessThan_h
      23             : #define __PLUMED_function_LessThan_h
      24             : #include "FunctionSetup.h"
      25             : #include "tools/SwitchingFunction.h"
      26             : 
      27             : #include <cmath>
      28             : 
      29             : namespace PLMD {
      30             : namespace function {
      31             : 
      32         244 : class LessThan {
      33             : public:
      34             :   bool squared;
      35             : #ifdef __PLUMED_HAS_OPENACC
      36             :   SwitchingFunctionAccelerable switchingFunction;
      37             : #else
      38             :   SwitchingFunction switchingFunction;
      39             : #endif //__PLUMED_HAS_OPENACC
      40             :   static void registerKeywords( Keywords& keys );
      41             :   static void read( LessThan& func,
      42             :                     ActionWithArguments* action,
      43             :                     FunctionOptions& options );
      44             :   static void calc( const LessThan& func,
      45             :                     bool noderiv,
      46             :                     const View<const double>& args,
      47             :                     FunctionOutput& funcout );
      48             : #ifdef __PLUMED_HAS_OPENACC
      49             :   void toACCDevice() const {
      50             : #pragma acc enter data copyin(this[0:1],squared)
      51             :     switchingFunction.toACCDevice();
      52             :   }
      53             :   void removeFromACCDevice() const {
      54             :     switchingFunction.removeFromACCDevice();
      55             : #pragma acc exit data delete(squared,this[0:1])
      56             :   }
      57             : #endif //__PLUMED_HAS_OPENACC
      58             : };
      59             : 
      60         496 : void LessThan::registerKeywords(Keywords& keys) {
      61         496 :   keys.add("compulsory","NN","6","The n parameter of the switching function ");
      62         496 :   keys.add("compulsory","MM","0","The m parameter of the switching function; 0 implies 2*NN");
      63         496 :   keys.add("compulsory","D_0","0.0","The d_0 parameter of the switching function");
      64         496 :   keys.add("compulsory","R_0","The r_0 parameter of the switching function");
      65         496 :   keys.add("optional","SWITCH","This keyword is used if you want to employ an alternative to the continuous switching function defined above. "
      66             :            "The following provides information on the switching functions that are available. "
      67             :            "When this keyword is present you no longer need the NN, MM, D_0 and R_0 keywords.");
      68         496 :   keys.addFlag("SQUARED",false,"is the input quantity the square of the value that you would like to apply the switching function to");
      69         992 :   keys.setValueDescription("scalar/vector/matrix","a function that is one if the input is less than a threshold");
      70         496 : }
      71             : 
      72         122 : void LessThan::read( LessThan& func, ActionWithArguments* action, FunctionOptions& options ) {
      73         122 :   options.derivativeZeroIfValueIsZero = true;
      74         122 :   if( action->getNumberOfArguments()!=1 ) {
      75          46 :     ActionWithVector* av = dynamic_cast<ActionWithVector*>( action );
      76          46 :     if( !av || (av && action->getNumberOfArguments()-av->getNumberOfMasks()!=1) ) {
      77           0 :       action->error("should only be one argument to less_than actions");
      78             :     }
      79             :   }
      80         122 :   if( action->getPntrToArgument(0)->isPeriodic() ) {
      81           0 :     action->error("cannot use this function on periodic functions");
      82             :   }
      83             : 
      84             : 
      85             :   std::string errors;
      86             :   std::string sfinput;
      87         244 :   action->parse("SWITCH",sfinput);
      88         122 :   if(sfinput.length()>0) {
      89         122 :     func.switchingFunction.set(sfinput,errors);
      90         122 :     if( errors.length()!=0 ) {
      91           0 :       action->error("problem reading SWITCH keyword : " + errors );
      92             :     }
      93             :   } else {
      94           0 :     int nn=6;
      95           0 :     int mm=0;
      96           0 :     double d0=0.0;
      97           0 :     double r0=0.0;
      98           0 :     action->parse("R_0",r0);
      99           0 :     if(r0<=0.0) {
     100           0 :       action->error("R_0 should be explicitly specified and positive");
     101             :     }
     102           0 :     action->parse("D_0",d0);
     103           0 :     action->parse("NN",nn);
     104           0 :     action->parse("MM",mm);
     105           0 :     func.switchingFunction.set(nn,mm,r0,d0);
     106             :   }
     107         122 :   action->log<<"  using switching function with cutoff "<<func.switchingFunction.description()<<"\n";
     108         122 :   action->parseFlag("SQUARED",func.squared);
     109         122 :   if( func.squared ) {
     110           1 :     action->log<<"  input quantity is square of quantity that switching function acts upon\n";
     111             :   }
     112         122 : }
     113             : 
     114      352964 : void LessThan::calc( const LessThan& func,
     115             :                      bool noderiv,
     116             :                      const View<const double>& args,
     117             :                      FunctionOutput& funcout ) {
     118             :   double d;
     119      352964 :   if( func.squared ) {
     120       13401 :     funcout.values[0] = func.switchingFunction.calculateSqr( args[0], d );
     121       13401 :     if( !noderiv ) {
     122        6700 :       funcout.derivs[0][0] = d/2;
     123             :     }
     124             :   } else {
     125      339563 :     funcout.values[0] = func.switchingFunction.calculate( args[0], d );
     126      339563 :     if( !noderiv ) {
     127       98868 :       funcout.derivs[0][0] = args[0]*d;
     128             :     }
     129             :   }
     130      352964 : }
     131             : 
     132             : }
     133             : }
     134             : 
     135             : 
     136             : #endif //__PLUMED_function_LessThan_h