void NodeBasedCellPopulationWithParticles<DIM>::UpdateParticlePositions(double dt)
{
    // Initialise vector of forces on particles
    std::vector<c_vector<double, DIM> > drdt(this->GetNumNodes());
    for (unsigned i=0; i<drdt.size(); i++)
    {
        drdt[i] = zero_vector<double>(DIM);
    }

    // Calculate forces on particles
    double damping_constant = this->GetDampingConstantNormal();
    for (unsigned i=0; i<drdt.size(); i++)
    {
        drdt[i] = this->GetNode(i)->rGetAppliedForce()/damping_constant;
    }

    for (typename AbstractMesh<DIM,DIM>::NodeIterator node_iter = this->mrMesh.GetNodeIteratorBegin();
         node_iter != this->mrMesh.GetNodeIteratorEnd();
         ++node_iter)
    {
        if (node_iter->IsParticle())
        {
            ChastePoint<DIM> new_point(node_iter->rGetLocation() + dt*drdt[node_iter->GetIndex()]);
            node_iter->SetPoint(new_point);
        }
    }
}
예제 #2
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void VertexCryptBoundaryForce<DIM>::AddForceContribution(AbstractCellPopulation<DIM>& rCellPopulation)
{
    // Helper variable that is a static cast of the cell population
    VertexBasedCellPopulation<DIM>* p_cell_population = static_cast<VertexBasedCellPopulation<DIM>*>(&rCellPopulation);

    // Throw an exception message if not using a VertexBasedCellPopulation
    if (dynamic_cast<VertexBasedCellPopulation<DIM>*>(&rCellPopulation) == nullptr)
    {
        EXCEPTION("VertexCryptBoundaryForce is to be used with VertexBasedCellPopulations only");
    }

    // Iterate over nodes
    for (typename AbstractMesh<DIM,DIM>::NodeIterator node_iter = p_cell_population->rGetMesh().GetNodeIteratorBegin();
         node_iter != p_cell_population->rGetMesh().GetNodeIteratorEnd();
         ++node_iter)
    {
        double y = node_iter->rGetLocation()[1]; // y-coordinate of node

        // If the node lies below the line y=0, then add the boundary force contribution to the node forces
        if (y < 0.0)
        {
            c_vector<double, DIM> boundary_force = zero_vector<double>(DIM);
            boundary_force[1] = mForceStrength*SmallPow(y, 2);

            node_iter->AddAppliedForceContribution(boundary_force);
        }
    }
}
예제 #3
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void ForwardEulerNumericalMethod<ELEMENT_DIM,SPACE_DIM>::UpdateAllNodePositions(double dt)
{
    if (!this->mUseUpdateNodeLocation)
    {
        // Apply forces to each cell, and save a vector of net forces F
        std::vector<c_vector<double, SPACE_DIM> > forces = this->ComputeForcesIncludingDamping();

        unsigned index = 0;
        for (typename AbstractMesh<ELEMENT_DIM, SPACE_DIM>::NodeIterator node_iter = this->mpCellPopulation->rGetMesh().GetNodeIteratorBegin();
             node_iter != this->mpCellPopulation->rGetMesh().GetNodeIteratorEnd();
             ++node_iter, ++index)
        {
            // Get the current node location and calculate the new location according to the forward Euler method
            const c_vector<double, SPACE_DIM>& r_old_location = node_iter->rGetLocation();
            c_vector<double, SPACE_DIM> displacement = dt * forces[index];

            // In the vertex-based case, the displacement may be scaled if the cell rearrangement threshold is exceeded
            this->DetectStepSizeExceptions(node_iter->GetIndex(), displacement, dt);

            c_vector<double, SPACE_DIM> new_location = r_old_location + displacement;
            this->SafeNodePositionUpdate(node_iter->GetIndex(), new_location);
        }
    }
    else
    {
        /*
         * If this type of cell population does not support the new numerical methods, delegate
         * updating node positions to the population itself.
         *
         * This only applies to NodeBasedCellPopulationWithBuskeUpdates.
         */
        this->mpCellPopulation->UpdateNodeLocations(dt);
    }
}