void ReferenceVariableVerletDynamics::update(const OpenMM::System& system, vector<Vec3>& atomCoordinates,
                                          vector<Vec3>& velocities,
                                          vector<Vec3>& forces, vector<double>& masses, double maxStepSize, double tolerance) {
    // first-time-through initialization

    int numberOfAtoms = system.getNumParticles();
    if (getTimeStep() == 0) {
       // invert masses

       for (int ii = 0; ii < numberOfAtoms; ii++) {
          if (masses[ii] == 0.0)
              inverseMasses[ii] = 0.0;
          else
              inverseMasses[ii] = 1.0/masses[ii];
       }
    }

    double error = 0.0;
    for (int i = 0; i < numberOfAtoms; ++i) {
        for (int j = 0; j < 3; ++j) {
            double xerror = inverseMasses[i]*forces[i][j];
            error += xerror*xerror;
        }
    }
    error = sqrt(error/(numberOfAtoms*3));
    double newStepSize = sqrt(getAccuracy()/error);
    if (getDeltaT() > 0.0f)
        newStepSize = std::min(newStepSize, getDeltaT()*2.0f); // For safety, limit how quickly dt can increase.
    if (newStepSize > getDeltaT() && newStepSize < 1.2f*getDeltaT())
        newStepSize = getDeltaT(); // Keeping dt constant between steps improves the behavior of the integrator.
    if (newStepSize > maxStepSize)
        newStepSize = maxStepSize;
    double vstep = 0.5f*(newStepSize+getDeltaT()); // The time interval by which to advance the velocities
    setDeltaT(newStepSize);
    for (int i = 0; i < numberOfAtoms; ++i) {
        if (masses[i] != 0.0)
            for (int j = 0; j < 3; ++j) {
                double vPrime = velocities[i][j] + inverseMasses[i]*forces[i][j]*vstep;
                xPrime[i][j] = atomCoordinates[i][j] + vPrime*getDeltaT();
            }
    }
    ReferenceConstraintAlgorithm* referenceConstraintAlgorithm = getReferenceConstraintAlgorithm();
    if (referenceConstraintAlgorithm)
        referenceConstraintAlgorithm->apply(atomCoordinates, xPrime, inverseMasses, tolerance);

   // Update the positions and velocities.

   double velocityScale = 1.0/getDeltaT();
   for (int i = 0; i < numberOfAtoms; ++i) {
       if (masses[i] != 0.0)
           for (int j = 0; j < 3; ++j) {
               velocities[i][j] = velocityScale*(xPrime[i][j] - atomCoordinates[i][j]);
               atomCoordinates[i][j] = xPrime[i][j];
           }
   }
   ReferenceVirtualSites::computePositions(system, atomCoordinates);
   incrementTimeStep();
}
Ejemplo n.º 2
0
void ReferenceVerletDynamics::update(const OpenMM::System& system, vector<RealVec>& atomCoordinates,
                                          vector<RealVec>& velocities,
                                          vector<RealVec>& forces, vector<RealOpenMM>& masses, RealOpenMM tolerance) {

   // ---------------------------------------------------------------------------------------

   static const char* methodName      = "\nReferenceVerletDynamics::update";

   static const RealOpenMM zero       =  0.0;
   static const RealOpenMM one        =  1.0;

   // ---------------------------------------------------------------------------------------

   // first-time-through initialization

   int numberOfAtoms = system.getNumParticles();
   if( getTimeStep() == 0 ){
      // invert masses

      for( int ii = 0; ii < numberOfAtoms; ii++ ){
         if (masses[ii] == zero)
             inverseMasses[ii] = zero;
         else
             inverseMasses[ii] = one/masses[ii];
      }
   }
   
   // Perform the integration.
   
   for (int i = 0; i < numberOfAtoms; ++i) {
       if (masses[i] != zero)
           for (int j = 0; j < 3; ++j) {
               velocities[i][j] += inverseMasses[i]*forces[i][j]*getDeltaT();
               xPrime[i][j] = atomCoordinates[i][j] + velocities[i][j]*getDeltaT();
           }
   }
   ReferenceConstraintAlgorithm* referenceConstraintAlgorithm = getReferenceConstraintAlgorithm();
   if (referenceConstraintAlgorithm)
      referenceConstraintAlgorithm->apply(atomCoordinates, xPrime, inverseMasses, tolerance);
   
   // Update the positions and velocities.
   
   RealOpenMM velocityScale = static_cast<RealOpenMM>( 1.0/getDeltaT() );
   for (int i = 0; i < numberOfAtoms; ++i) {
       if (masses[i] != zero)
           for (int j = 0; j < 3; ++j) {
               velocities[i][j] = velocityScale*(xPrime[i][j] - atomCoordinates[i][j]);
               atomCoordinates[i][j] = xPrime[i][j];
           }
   }

   ReferenceVirtualSites::computePositions(system, atomCoordinates);
   incrementTimeStep();
}
Ejemplo n.º 3
0
void ReferenceBrownianDynamics::update(const OpenMM::System& system, vector<RealVec>& atomCoordinates,
                                          vector<RealVec>& velocities,
                                          vector<RealVec>& forces, vector<RealOpenMM>& masses, RealOpenMM tolerance) {

   // ---------------------------------------------------------------------------------------

   static const char* methodName      = "\nReferenceBrownianDynamics::update";

   static const RealOpenMM zero       =  0.0;
   static const RealOpenMM one        =  1.0;

   // ---------------------------------------------------------------------------------------

   // first-time-through initialization

   int numberOfAtoms = system.getNumParticles();
   if( getTimeStep() == 0 ){
      // invert masses

      for( int ii = 0; ii < numberOfAtoms; ii++ ){
         if (masses[ii] == zero)
             inverseMasses[ii] = zero;
         else
             inverseMasses[ii] = one/masses[ii];
      }
   }
   
   // Perform the integration.
   
   const RealOpenMM noiseAmplitude = static_cast<RealOpenMM>( sqrt(2.0*BOLTZ*getTemperature()*getDeltaT()/getFriction()) );
   const RealOpenMM forceScale = getDeltaT()/getFriction();
   for (int i = 0; i < numberOfAtoms; ++i) {
       if (masses[i] != zero)
           for (int j = 0; j < 3; ++j) {
               xPrime[i][j] = atomCoordinates[i][j] + forceScale*inverseMasses[i]*forces[i][j] + noiseAmplitude*SQRT(inverseMasses[i])*SimTKOpenMMUtilities::getNormallyDistributedRandomNumber();
           }
   }
   ReferenceConstraintAlgorithm* referenceConstraintAlgorithm = getReferenceConstraintAlgorithm();
   if (referenceConstraintAlgorithm)
      referenceConstraintAlgorithm->apply(atomCoordinates, xPrime, inverseMasses, tolerance);
   
   // Update the positions and velocities.
   
   RealOpenMM velocityScale = static_cast<RealOpenMM>( 1.0/getDeltaT() );
   for (int i = 0; i < numberOfAtoms; ++i) {
       if (masses[i] != zero)
           for (int j = 0; j < 3; ++j) {
               velocities[i][j] = velocityScale*(xPrime[i][j] - atomCoordinates[i][j]);
               atomCoordinates[i][j] = xPrime[i][j];
           }
   }
   ReferenceVirtualSites::computePositions(system, atomCoordinates);
   incrementTimeStep();
}
void ReferenceStochasticDynamics::update(const OpenMM::System& system, vector<RealVec>& atomCoordinates,
                                          vector<RealVec>& velocities, vector<RealVec>& forces, vector<RealOpenMM>& masses, RealOpenMM tolerance) {

   // ---------------------------------------------------------------------------------------

   static const char* methodName      = "\nReferenceStochasticDynamics::update";

   static const RealOpenMM zero       =  0.0;
   static const RealOpenMM one        =  1.0;

   // ---------------------------------------------------------------------------------------

   // first-time-through initialization

   int numberOfAtoms = system.getNumParticles();
   if( getTimeStep() == 0 ){
      // invert masses

      for( int ii = 0; ii < numberOfAtoms; ii++ ){
         if (masses[ii] == zero)
             inverseMasses[ii] = zero;
         else
             inverseMasses[ii] = one/masses[ii];
      }
   }

   // 1st update

   updatePart1( numberOfAtoms, atomCoordinates, velocities, forces, inverseMasses, xPrime );

   // 2nd update

   updatePart2( numberOfAtoms, atomCoordinates, velocities, forces, inverseMasses, xPrime );

   ReferenceConstraintAlgorithm* referenceConstraintAlgorithm = getReferenceConstraintAlgorithm();
   if (referenceConstraintAlgorithm)
      referenceConstraintAlgorithm->apply(atomCoordinates, xPrime, inverseMasses, tolerance);

   // copy xPrime -> atomCoordinates

   RealOpenMM invStepSize = 1.0/getDeltaT();
   for (int i = 0; i < numberOfAtoms; ++i)
       if (masses[i] != zero)
           for (int j = 0; j < 3; ++j) {
               velocities[i][j] = invStepSize*(xPrime[i][j]-atomCoordinates[i][j]);
               atomCoordinates[i][j] = xPrime[i][j];
           }

   ReferenceVirtualSites::computePositions(system, atomCoordinates);
   incrementTimeStep();
}
Ejemplo n.º 5
0
TEST(TestControlBerendsenBins,SingleBin){
    std::ifstream file("../foam-1728.json");
    if(!file.is_open()){
        std::cout<<"File not found"<<std::endl;
        exit(0);
    }
    
    std::string jsonstr;
    std::string line;
    while (!file.eof()) {
        getline(file, line);
        jsonstr += line;
    }
    file.close();
    
    rapidjson::Document document;
    if(document.Parse<0>(jsonstr.c_str()).HasParseError()){
        std::cout<<"Parsing error "<<std::endl;
        exit(0);
    }
    
    const double stepSizeInFs = document["StepSizeInFs"].GetDouble();
    const int numParticles = document["NumberAtoms"].GetInt();
    std::string equationStr = document["Equation"].GetString();
    const double rCut = document["rCut"].GetDouble();
    const rapidjson::Value& b = document["Boxsize"];
    double bx = b[(rapidjson::SizeType)0].GetDouble();
    double by = b[(rapidjson::SizeType)1].GetDouble();
    double bz = b[(rapidjson::SizeType)2].GetDouble();
    int numSpecies = document["NumberSpecies"].GetInt();
    std::vector<OpenMM::Vec3> posInNm;
    std::vector<OpenMM::Vec3> velInNm;
    
    OpenMM::Platform::loadPluginsFromDirectory(
           OpenMM::Platform::getDefaultPluginsDirectory());
    
    OpenMM::System system;
    //add particles to the system by reading from json file
    system.setDefaultPeriodicBoxVectors(OpenMM::Vec3(bx,0,0),OpenMM::Vec3(0,by,0),OpenMM::Vec3(0,0,bz));
    const rapidjson::Value& mass = document["masses"];
    const rapidjson::Value& pos = document["Positions"];
    const rapidjson::Value& vel = document["Velocities"];
    
    posInNm.clear();
    velInNm.clear();
    for(rapidjson::SizeType m=0;m<mass.Size();m++){
        double tm = mass[(rapidjson::SizeType) m].GetDouble();
        system.addParticle(tm);
        posInNm.push_back(OpenMM::Vec3(pos[(rapidjson::SizeType) m]["0"].GetDouble(),
                                       pos[(rapidjson::SizeType) m]["1"].GetDouble(),
                                       pos[(rapidjson::SizeType) m]["2"].GetDouble()
                                       ));
        velInNm.push_back(OpenMM::Vec3(vel[(rapidjson::SizeType) m]["0"].GetDouble(),
                                       vel[(rapidjson::SizeType) m]["1"].GetDouble(),
                                       vel[(rapidjson::SizeType) m]["2"].GetDouble()
                                       ));
    }
    std::cout<<"Initialized System with "<<system.getNumParticles()<<" Particles."<<std::endl;
    
    OpenMM::CustomNonbondedForce* nonbonded = new OpenMM::CustomNonbondedForce(equationStr);
    nonbonded->setNonbondedMethod(OpenMM::CustomNonbondedForce::CutoffPeriodic);
    nonbonded->setCutoffDistance(rCut);// * OpenMM::NmPerAngstrom
    nonbonded->addPerParticleParameter("Ar");//later on collect it from json string based on OF
    for(int p=0;p<numParticles;p++){
        std::vector<double> params(numSpecies);
        params[0] = (double) 1;
        nonbonded->addParticle(params);
    }
    system.addForce(nonbonded);
    std::vector<std::string> ctools(1);
    ctools[0] = "ControlBerendsenInBins";
    OpenMM::Vec3 startPoint = OpenMM::Vec3((10*0.34),(0*0.34),(10*0.34));
    OpenMM::Vec3 endPoint = OpenMM::Vec3((10*0.34),(20*0.34),(10*0.34));
    OpenMM::ControlTools controls(ctools,(double)292,0.001,
                                  startPoint,endPoint);
    int num_plat = OpenMM::Platform::getNumPlatforms();
    std::cout<<"Number of registered platforms: "<< num_plat <<std::endl;
    for(int i=0;i<num_plat;i++)
    {
	    OpenMM::Platform& tempPlatform = OpenMM::Platform::getPlatform(i);
	    std::string tempPlatformName = tempPlatform.getName();
	    std::cout<<"Platform "<<(i+1)<<" is "<<tempPlatformName.c_str()<<std::endl;
    }
    OpenMM::Platform& platform = OpenMM::Platform::getPlatformByName("OpenCL");
    OpenMM::VelocityVerletIntegrator integrator(stepSizeInFs * OpenMM::PsPerFs);
    OpenMM::Context context(system,integrator,platform,controls);
    string Platformname = context.getPlatform().getName();
    std::cout<<"Using OpenMM "<<Platformname.c_str()<<" Platform"<<std::endl;

    context.setPositions(posInNm);
    context.setVelocities(velInNm);
    
    int nbs = context.getControls().getNBins();
    printf("Using %d bins for the system\n",nbs);
    //start the simulation loop
    integrator.step(1);
    printf("Finished initial integration\n");
    int counter=0;
    std::cout<<"starting the loop\n";
    for(int frame=1;frame<400;++frame){
//        OpenMM::State state = context.getState(OpenMM::State::Velocities);
//        const double time = state.getTime();
            double* mola = context.getControls().getBinTemperature();
//            OpenMM::Vec3* tv = context.getControls().getTestVariable();
            double gpuMol = 0.0;
            for(int k=0;k<nbs;k++){
                gpuMol += mola[k];
            }
        EXPECT_EQ((double) numParticles,gpuMol);
        integrator.step(1);
    }
    std::cout<<"Simulation completed with counter value "<<counter<<std::endl;
}