C++ NonbondedForce::getUseSwitchingFunction方法代码示例

double NonbondedForceImpl::calcDispersionCorrection(const System& system, const NonbondedForce& force) {
    if (force.getNonbondedMethod() == NonbondedForce::NoCutoff || force.getNonbondedMethod() == NonbondedForce::CutoffNonPeriodic)
        return 0.0;
    
    // Identify all particle classes (defined by sigma and epsilon), and count the number of
    // particles in each class.

    map<pair<double, double>, int> classCounts;
    for (int i = 0; i < force.getNumParticles(); i++) {
        double charge, sigma, epsilon;
        force.getParticleParameters(i, charge, sigma, epsilon);
        pair<double, double> key = make_pair(sigma, epsilon);
        map<pair<double, double>, int>::iterator entry = classCounts.find(key);
        if (entry == classCounts.end())
            classCounts[key] = 1;
        else
            entry->second++;
    }

    // Loop over all pairs of classes to compute the coefficient.

    double sum1 = 0, sum2 = 0, sum3 = 0;
    bool useSwitch = force.getUseSwitchingFunction();
    double cutoff = force.getCutoffDistance();
    double switchDist = force.getSwitchingDistance();
    for (map<pair<double, double>, int>::const_iterator entry = classCounts.begin(); entry != classCounts.end(); ++entry) {
        double sigma = entry->first.first;
        double epsilon = entry->first.second;
        double count = (double) entry->second;
        count *= (count + 1) / 2;
        double sigma2 = sigma*sigma;
        double sigma6 = sigma2*sigma2*sigma2;
        sum1 += count*epsilon*sigma6*sigma6;
        sum2 += count*epsilon*sigma6;
        if (useSwitch)
            sum3 += count*epsilon*(evalIntegral(cutoff, switchDist, cutoff, sigma)-evalIntegral(switchDist, switchDist, cutoff, sigma));
    }
    for (map<pair<double, double>, int>::const_iterator class1 = classCounts.begin(); class1 != classCounts.end(); ++class1)
        for (map<pair<double, double>, int>::const_iterator class2 = classCounts.begin(); class2 != class1; ++class2) {
            double sigma = 0.5*(class1->first.first+class2->first.first);
            double epsilon = sqrt(class1->first.second*class2->first.second);
            double count = (double) class1->second;
            count *= (double) class2->second;
            double sigma2 = sigma*sigma;
            double sigma6 = sigma2*sigma2*sigma2;
            sum1 += count*epsilon*sigma6*sigma6;
            sum2 += count*epsilon*sigma6;
            if (useSwitch)
                sum3 += count*epsilon*(evalIntegral(cutoff, switchDist, cutoff, sigma)-evalIntegral(switchDist, switchDist, cutoff, sigma));
        }
    double numParticles = (double) system.getNumParticles();
    double numInteractions = (numParticles*(numParticles+1))/2;
    sum1 /= numInteractions;
    sum2 /= numInteractions;
    sum3 /= numInteractions;
    return 8*numParticles*numParticles*M_PI*(sum1/(9*pow(cutoff, 9))-sum2/(3*pow(cutoff, 3))+sum3);
}

void CpuCalcNonbondedForceKernel::initialize(const System& system, const NonbondedForce& force) {

    // Identify which exceptions are 1-4 interactions.

    numParticles = force.getNumParticles();
    exclusions.resize(numParticles);
    vector<int> nb14s;
    for (int i = 0; i < force.getNumExceptions(); i++) {
        int particle1, particle2;
        double chargeProd, sigma, epsilon;
        force.getExceptionParameters(i, particle1, particle2, chargeProd, sigma, epsilon);
        exclusions[particle1].insert(particle2);
        exclusions[particle2].insert(particle1);
        if (chargeProd != 0.0 || epsilon != 0.0)
            nb14s.push_back(i);
    }

    // Record the particle parameters.

    num14 = nb14s.size();
    bonded14IndexArray = new int*[num14];
    for (int i = 0; i < num14; i++)
        bonded14IndexArray[i] = new int[2];
    bonded14ParamArray = new double*[num14];
    for (int i = 0; i < num14; i++)
        bonded14ParamArray[i] = new double[3];
    particleParams.resize(numParticles);
    double sumSquaredCharges = 0.0;
    for (int i = 0; i < numParticles; ++i) {
        double charge, radius, depth;
        force.getParticleParameters(i, charge, radius, depth);
        data.posq[4*i+3] = (float) charge;
        particleParams[i] = make_pair((float) (0.5*radius), (float) (2.0*sqrt(depth)));
        sumSquaredCharges += charge*charge;
    }
    
    // Recorded exception parameters.
    
    for (int i = 0; i < num14; ++i) {
        int particle1, particle2;
        double charge, radius, depth;
        force.getExceptionParameters(nb14s[i], particle1, particle2, charge, radius, depth);
        bonded14IndexArray[i][0] = particle1;
        bonded14IndexArray[i][1] = particle2;
        bonded14ParamArray[i][0] = static_cast<RealOpenMM>(radius);
        bonded14ParamArray[i][1] = static_cast<RealOpenMM>(4.0*depth);
        bonded14ParamArray[i][2] = static_cast<RealOpenMM>(charge);
    }
    
    // Record other parameters.
    
    nonbondedMethod = CalcNonbondedForceKernel::NonbondedMethod(force.getNonbondedMethod());
    nonbondedCutoff = force.getCutoffDistance();
    if (nonbondedMethod == NoCutoff)
        useSwitchingFunction = false;
    else {
        useSwitchingFunction = force.getUseSwitchingFunction();
        switchingDistance = force.getSwitchingDistance();
    }
    if (nonbondedMethod == Ewald) {
        double alpha;
        NonbondedForceImpl::calcEwaldParameters(system, force, alpha, kmax[0], kmax[1], kmax[2]);
        ewaldAlpha = alpha;
    }
    else if (nonbondedMethod == PME) {
        double alpha;
        NonbondedForceImpl::calcPMEParameters(system, force, alpha, gridSize[0], gridSize[1], gridSize[2]);
        ewaldAlpha = alpha;
    }
    if (nonbondedMethod == Ewald || nonbondedMethod == PME)
        ewaldSelfEnergy = -ONE_4PI_EPS0*ewaldAlpha*sumSquaredCharges/sqrt(M_PI);
    else
        ewaldSelfEnergy = 0.0;
    rfDielectric = force.getReactionFieldDielectric();
    if (force.getUseDispersionCorrection())
        dispersionCoefficient = NonbondedForceImpl::calcDispersionCorrection(system, force);
    else
        dispersionCoefficient = 0.0;
    lastPositions.resize(numParticles, Vec3(1e10, 1e10, 1e10));
    data.isPeriodic = (nonbondedMethod == CutoffPeriodic || nonbondedMethod == Ewald || nonbondedMethod == PME);
}

void testSerialization() {
    // Create a Force.

    NonbondedForce force;
    force.setForceGroup(3);
    force.setNonbondedMethod(NonbondedForce::CutoffPeriodic);
    force.setSwitchingDistance(1.5);
    force.setUseSwitchingFunction(true);
    force.setCutoffDistance(2.0);
    force.setEwaldErrorTolerance(1e-3);
    force.setReactionFieldDielectric(50.0);
    force.setUseDispersionCorrection(false);
    double alpha = 0.5;
    int nx = 3, ny = 5, nz = 7;
    force.setPMEParameters(alpha, nx, ny, nz);
    double dalpha = 0.8;
    int dnx = 4, dny = 6, dnz = 7;
    force.setLJPMEParameters(dalpha, dnx, dny, dnz);
    force.addParticle(1, 0.1, 0.01);
    force.addParticle(0.5, 0.2, 0.02);
    force.addParticle(-0.5, 0.3, 0.03);
    force.addException(0, 1, 2, 0.5, 0.1);
    force.addException(1, 2, 0.2, 0.4, 0.2);
    force.addGlobalParameter("scale1", 1.0);
    force.addGlobalParameter("scale2", 2.0);
    force.addParticleParameterOffset("scale1", 2, 1.5, 2.0, 2.5);
    force.addExceptionParameterOffset("scale2", 1, -0.1, -0.2, -0.3);

    // Serialize and then deserialize it.

    stringstream buffer;
    XmlSerializer::serialize<NonbondedForce>(&force, "Force", buffer);
    NonbondedForce* copy = XmlSerializer::deserialize<NonbondedForce>(buffer);

    // Compare the two forces to see if they are identical.

    NonbondedForce& force2 = *copy;
    ASSERT_EQUAL(force.getForceGroup(), force2.getForceGroup());
    ASSERT_EQUAL(force.getNonbondedMethod(), force2.getNonbondedMethod());
    ASSERT_EQUAL(force.getSwitchingDistance(), force2.getSwitchingDistance());
    ASSERT_EQUAL(force.getUseSwitchingFunction(), force2.getUseSwitchingFunction());
    ASSERT_EQUAL(force.getCutoffDistance(), force2.getCutoffDistance());
    ASSERT_EQUAL(force.getEwaldErrorTolerance(), force2.getEwaldErrorTolerance());
    ASSERT_EQUAL(force.getReactionFieldDielectric(), force2.getReactionFieldDielectric());
    ASSERT_EQUAL(force.getUseDispersionCorrection(), force2.getUseDispersionCorrection());
    ASSERT_EQUAL(force.getNumParticles(), force2.getNumParticles());
    ASSERT_EQUAL(force.getNumExceptions(), force2.getNumExceptions());
    ASSERT_EQUAL(force.getNumGlobalParameters(), force2.getNumGlobalParameters());
    ASSERT_EQUAL(force.getNumParticleParameterOffsets(), force2.getNumParticleParameterOffsets());
    ASSERT_EQUAL(force.getNumExceptionParameterOffsets(), force2.getNumExceptionParameterOffsets());
    double alpha2;
    int nx2, ny2, nz2;
    force2.getPMEParameters(alpha2, nx2, ny2, nz2);
    ASSERT_EQUAL(alpha, alpha2);
    ASSERT_EQUAL(nx, nx2);
    ASSERT_EQUAL(ny, ny2);
    ASSERT_EQUAL(nz, nz2);    
    double dalpha2;
    int dnx2, dny2, dnz2;
    force2.getLJPMEParameters(dalpha2, dnx2, dny2, dnz2);
    ASSERT_EQUAL(dalpha, dalpha2);
    ASSERT_EQUAL(dnx, dnx2);
    ASSERT_EQUAL(dny, dny2);
    ASSERT_EQUAL(dnz, dnz2);
    for (int i = 0; i < force.getNumGlobalParameters(); i++) {
        ASSERT_EQUAL(force.getGlobalParameterName(i), force2.getGlobalParameterName(i));
        ASSERT_EQUAL(force.getGlobalParameterDefaultValue(i), force2.getGlobalParameterDefaultValue(i));
    }
    for (int i = 0; i < force.getNumParticleParameterOffsets(); i++) {
        int index1, index2;
        string param1, param2;
        double charge1, sigma1, epsilon1;
        double charge2, sigma2, epsilon2;
        force.getParticleParameterOffset(i, param1, index1, charge1, sigma1, epsilon1);
        force2.getParticleParameterOffset(i, param2, index2, charge2, sigma2, epsilon2);
        ASSERT_EQUAL(index1, index1);
        ASSERT_EQUAL(param1, param2);
        ASSERT_EQUAL(charge1, charge2);
        ASSERT_EQUAL(sigma1, sigma2);
        ASSERT_EQUAL(epsilon1, epsilon2);
    }
    for (int i = 0; i < force.getNumExceptionParameterOffsets(); i++) {
        int index1, index2;
        string param1, param2;
        double charge1, sigma1, epsilon1;
        double charge2, sigma2, epsilon2;
        force.getExceptionParameterOffset(i, param1, index1, charge1, sigma1, epsilon1);
        force2.getExceptionParameterOffset(i, param2, index2, charge2, sigma2, epsilon2);
        ASSERT_EQUAL(index1, index1);
        ASSERT_EQUAL(param1, param2);
        ASSERT_EQUAL(charge1, charge2);
        ASSERT_EQUAL(sigma1, sigma2);
        ASSERT_EQUAL(epsilon1, epsilon2);
    }
    for (int i = 0; i < force.getNumParticles(); i++) {
        double charge1, sigma1, epsilon1;
        double charge2, sigma2, epsilon2;
        force.getParticleParameters(i, charge1, sigma1, epsilon1);
        force2.getParticleParameters(i, charge2, sigma2, epsilon2);
        ASSERT_EQUAL(charge1, charge2);
//.........这里部分代码省略.........