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

void testSerialization() {
    // Create a Force.

    NonbondedForce force;
    force.setNonbondedMethod(NonbondedForce::CutoffPeriodic);
    force.setCutoffDistance(2.0);
    force.setEwaldErrorTolerance(1e-3);
    force.setReactionFieldDielectric(50.0);
    force.setUseDispersionCorrection(false);
    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);

    // 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.getNonbondedMethod(), force2.getNonbondedMethod());
    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());
    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);
        ASSERT_EQUAL(sigma1, sigma2);
        ASSERT_EQUAL(epsilon1, epsilon2);
    }
    ASSERT_EQUAL(force.getNumExceptions(), force2.getNumExceptions());
    for (int i = 0; i < force.getNumExceptions(); i++) {
        int a1, a2, b1, b2;
        double charge1, sigma1, epsilon1;
        double charge2, sigma2, epsilon2;
        force.getExceptionParameters(i, a1, b1, charge1, sigma1, epsilon1);
        force2.getExceptionParameters(i, a2, b2, charge2, sigma2, epsilon2);
        ASSERT_EQUAL(a1, a2);
        ASSERT_EQUAL(b1, b2);
        ASSERT_EQUAL(charge1, charge2);
        ASSERT_EQUAL(sigma1, sigma2);
        ASSERT_EQUAL(epsilon1, epsilon2);
    }
}

void ValidateOpenMM::writeNonbondedForce( FILE* filePtr, const NonbondedForce & nonbondedForce ) const {

    // charge and vdw parameters

    (void) fprintf( filePtr, "NonbondedForce %d\n", nonbondedForce.getNumParticles() );
    for(int ii = 0; ii < nonbondedForce.getNumParticles(); ii++ ){
       double charge, sigma, epsilon;
       nonbondedForce.getParticleParameters( ii, charge, sigma, epsilon );
       (void) fprintf( filePtr, "%8d %14.7e %14.7e %14.7e\n", ii, charge, sigma, epsilon );
    }

    // cutoff, dielectric, Ewald tolerance

    (void) fprintf( filePtr, "CutoffDistance %14.7e\n", nonbondedForce.getCutoffDistance() );
    (void) fprintf( filePtr, "RFDielectric %14.7e\n", nonbondedForce.getReactionFieldDielectric() );
    (void) fprintf( filePtr, "EwaldRTolerance %14.7e\n", nonbondedForce.getEwaldErrorTolerance() );

    // cutoff mode

    std::string nonbondedForceMethod;
    switch( nonbondedForce.getNonbondedMethod() ){
        case NonbondedForce::NoCutoff:
            nonbondedForceMethod = "NoCutoff";
            break;
        case NonbondedForce::CutoffNonPeriodic:
            nonbondedForceMethod = "CutoffNonPeriodic";
            break;
        case NonbondedForce::CutoffPeriodic:
            nonbondedForceMethod = "CutoffPeriodic";
            break;
        case NonbondedForce::Ewald:
            nonbondedForceMethod = "Ewald";
            break;
        case NonbondedForce::PME:
            nonbondedForceMethod = "PME";
            break;
        default:
            nonbondedForceMethod = "Unknown";
    }
    (void) fprintf( filePtr, "NonbondedForceMethod %s\n", nonbondedForceMethod.c_str() );

    (void) fprintf( filePtr, "NonbondedForceExceptions %d\n", nonbondedForce.getNumExceptions() );
    for(int ii = 0; ii < nonbondedForce.getNumExceptions(); ii++ ){
       int particle1, particle2;
       double chargeProd, sigma, epsilon;
       nonbondedForce.getExceptionParameters( ii, particle1, particle2, chargeProd, sigma, epsilon );
       (void) fprintf( filePtr, "%8d %8d %8d %14.7e %14.7e %14.7e\n", ii, particle1, particle2, chargeProd, sigma, epsilon );
    }

}

void CpuCalcNonbondedForceKernel::copyParametersToContext(ContextImpl& context, const NonbondedForce& force) {
    if (force.getNumParticles() != numParticles)
        throw OpenMMException("updateParametersInContext: The number of particles has changed");
    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);
        if (chargeProd != 0.0 || epsilon != 0.0)
            nb14s.push_back(i);
    }
    if (nb14s.size() != num14)
        throw OpenMMException("updateParametersInContext: The number of non-excluded exceptions has changed");

    // Record the values.

    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;
    }
    if (nonbondedMethod == Ewald || nonbondedMethod == PME)
        ewaldSelfEnergy = -ONE_4PI_EPS0*ewaldAlpha*sumSquaredCharges/sqrt(M_PI);
    else
        ewaldSelfEnergy = 0.0;
    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);
    }
    
    // Recompute the coefficient for the dispersion correction.

    NonbondedForce::NonbondedMethod method = force.getNonbondedMethod();
    if (force.getUseDispersionCorrection() && (method == NonbondedForce::CutoffPeriodic || method == NonbondedForce::Ewald || method == NonbondedForce::PME))
        dispersionCoefficient = NonbondedForceImpl::calcDispersionCorrection(context.getSystem(), force);
}

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.........

void testCutoff14() {
    System system;
    VerletIntegrator integrator(0.01);
    NonbondedForce* nonbonded = new NonbondedForce();
    nonbonded->setNonbondedMethod(NonbondedForce::CutoffNonPeriodic);
    for (int i = 0; i < 5; ++i) {
        system.addParticle(1.0);
        nonbonded->addParticle(0, 1.5, 0);
    }
    const double cutoff = 3.5;
    nonbonded->setCutoffDistance(cutoff);
    const double eps = 30.0;
    nonbonded->setReactionFieldDielectric(eps);
    vector<pair<int, int> > bonds;
    bonds.push_back(pair<int, int>(0, 1));
    bonds.push_back(pair<int, int>(1, 2));
    bonds.push_back(pair<int, int>(2, 3));
    bonds.push_back(pair<int, int>(3, 4));
    nonbonded->createExceptionsFromBonds(bonds, 0.0, 0.0);
    int first14, second14;
    for (int i = 0; i < nonbonded->getNumExceptions(); i++) {
        int particle1, particle2;
        double chargeProd, sigma, epsilon;
        nonbonded->getExceptionParameters(i, particle1, particle2, chargeProd, sigma, epsilon);
        if ((particle1 == 0 && particle2 == 3) || (particle1 == 3 && particle2 == 0))
            first14 = i;
        if ((particle1 == 1 && particle2 == 4) || (particle1 == 4 && particle2 == 1))
            second14 = i;
    }
    system.addForce(nonbonded);
    Context context(system, integrator, platform);
    vector<Vec3> positions(5);
    positions[0] = Vec3(0, 0, 0);
    positions[1] = Vec3(1, 0, 0);
    positions[2] = Vec3(2, 0, 0);
    positions[3] = Vec3(3, 0, 0);
    positions[4] = Vec3(4, 0, 0);
    for (int i = 1; i < 5; ++i) {

        // Test LJ forces

        nonbonded->setParticleParameters(0, 0, 1.5, 1);
        for (int j = 1; j < 5; ++j)
            nonbonded->setParticleParameters(j, 0, 1.5, 0);
        nonbonded->setParticleParameters(i, 0, 1.5, 1);
        nonbonded->setExceptionParameters(first14, 0, 3, 0, 1.5, i == 3 ? 0.5 : 0.0);
        nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0.0);
        context.reinitialize();
        context.setPositions(positions);
        State state = context.getState(State::Forces | State::Energy);
        const vector<Vec3>& forces = state.getForces();
        double r = positions[i][0];
        double x = 1.5/r;
        double e = 1.0;
        double force = 4.0*e*(12*std::pow(x, 12.0)-6*std::pow(x, 6.0))/r;
        double energy = 4.0*e*(std::pow(x, 12.0)-std::pow(x, 6.0));
        if (i == 3) {
            force *= 0.5;
            energy *= 0.5;
        }
        if (i < 3 || r > cutoff) {
            force = 0;
            energy = 0;
        }
        ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[0], TOL);
        ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[i], TOL);
        ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);

        // Test Coulomb forces

        const double q = 0.7;
        nonbonded->setParticleParameters(0, q, 1.5, 0);
        nonbonded->setParticleParameters(i, q, 1.5, 0);
        nonbonded->setExceptionParameters(first14, 0, 3, i == 3 ? q*q/1.2 : 0, 1.5, 0);
        nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0);
        context.reinitialize();
        context.setPositions(positions);
        state = context.getState(State::Forces | State::Energy);
        const vector<Vec3>& forces2 = state.getForces();
        force = ONE_4PI_EPS0*q*q/(r*r);
        energy = ONE_4PI_EPS0*q*q/r;
        if (i == 3) {
            force /= 1.2;
            energy /= 1.2;
        }
        if (i < 3 || r > cutoff) {
            force = 0;
            energy = 0;
        }
        ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces2[0], TOL);
        ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces2[i], TOL);
        ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
    }
}

void testExclusionsAnd14() {
    System system;
    NonbondedForce* nonbonded = new NonbondedForce();
    for (int i = 0; i < 5; ++i) {
        system.addParticle(1.0);
        nonbonded->addParticle(0, 1.5, 0);
    }
    vector<pair<int, int> > bonds;
    bonds.push_back(pair<int, int>(0, 1));
    bonds.push_back(pair<int, int>(1, 2));
    bonds.push_back(pair<int, int>(2, 3));
    bonds.push_back(pair<int, int>(3, 4));
    nonbonded->createExceptionsFromBonds(bonds, 0.0, 0.0);
    int first14, second14;
    for (int i = 0; i < nonbonded->getNumExceptions(); i++) {
        int particle1, particle2;
        double chargeProd, sigma, epsilon;
        nonbonded->getExceptionParameters(i, particle1, particle2, chargeProd, sigma, epsilon);
        if ((particle1 == 0 && particle2 == 3) || (particle1 == 3 && particle2 == 0))
            first14 = i;
        if ((particle1 == 1 && particle2 == 4) || (particle1 == 4 && particle2 == 1))
            second14 = i;
    }
    system.addForce(nonbonded);
    VerletIntegrator integrator(0.01);
    Context context(system, integrator, platform);
    for (int i = 1; i < 5; ++i) {

        // Test LJ forces

        vector<Vec3> positions(5);
        const double r = 1.0;
        for (int j = 0; j < 5; ++j) {
            nonbonded->setParticleParameters(j, 0, 1.5, 0);
            positions[j] = Vec3(0, j, 0);
        }
        nonbonded->setParticleParameters(0, 0, 1.5, 1);
        nonbonded->setParticleParameters(i, 0, 1.5, 1);
        nonbonded->setExceptionParameters(first14, 0, 3, 0, 1.5, i == 3 ? 0.5 : 0.0);
        nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0.0);
        positions[i] = Vec3(r, 0, 0);
        context.reinitialize();
        context.setPositions(positions);
        State state = context.getState(State::Forces | State::Energy);
        const vector<Vec3>& forces = state.getForces();
        double x = 1.5/r;
        double eps = 1.0;
        double force = 4.0*eps*(12*std::pow(x, 12.0)-6*std::pow(x, 6.0))/r;
        double energy = 4.0*eps*(std::pow(x, 12.0)-std::pow(x, 6.0));
        if (i == 3) {
            force *= 0.5;
            energy *= 0.5;
        }
        if (i < 3) {
            force = 0;
            energy = 0;
        }
        ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces[0], TOL);
        ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces[i], TOL);
        ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);

        // Test Coulomb forces

        nonbonded->setParticleParameters(0, 2, 1.5, 0);
        nonbonded->setParticleParameters(i, 2, 1.5, 0);
        nonbonded->setExceptionParameters(first14, 0, 3, i == 3 ? 4/1.2 : 0, 1.5, 0);
        nonbonded->setExceptionParameters(second14, 1, 4, 0, 1.5, 0);
        context.reinitialize();
        context.setPositions(positions);
        state = context.getState(State::Forces | State::Energy);
        const vector<Vec3>& forces2 = state.getForces();
        force = ONE_4PI_EPS0*4/(r*r);
        energy = ONE_4PI_EPS0*4/r;
        if (i == 3) {
            force /= 1.2;
            energy /= 1.2;
        }
        if (i < 3) {
            force = 0;
            energy = 0;
        }
        ASSERT_EQUAL_VEC(Vec3(-force, 0, 0), forces2[0], TOL);
        ASSERT_EQUAL_VEC(Vec3(force, 0, 0), forces2[i], TOL);
        ASSERT_EQUAL_TOL(energy, state.getPotentialEnergy(), TOL);
    }
}