Migrate from dune-fufem to dune-functions bases

Migrate from dune-fufem to dune-functions bases.

dune/gfe/geodesicfeassemblerwrapper.hh

+#ifndef GLOBAL_GEODESIC_FE_ASSEMBLER_WRAPPER_HH
+#define GLOBAL_GEODESIC_FE_ASSEMBLER_WRAPPER_HH
+
+#include <dune/gfe/mixedgfeassembler.hh>
+#include <dune/common/tuplevector.hh>
+
+/** \brief A wrapper that wraps a MixedGFEAssembler into an assembler that does not distinguish between the two Finite Element Spaces
+           It reimplements the same methods as these two and transfers the structure of the gradient and the Hessian
+ */
+template <class Basis, class ScalarBasis, class TargetSpace, class MixedSpace0, class MixedSpace1>
+class 
+GeodesicFEAssemblerWrapper {
+
+    typedef typename Basis::GridView GridView;
+
+    //! Dimension of the grid.
+    enum { gridDim = GridView::dimension };
+
+    //! Dimension of the tangent space
+    enum { blocksize = TargetSpace::TangentVector::dimension };
+    enum { blocksize0 = MixedSpace0::TangentVector::dimension };
+    enum { blocksize1 = MixedSpace1::TangentVector::dimension };
+
+    //!
+    typedef Dune::FieldMatrix<double, blocksize, blocksize> MatrixBlock;
+    typedef typename MixedGFEAssembler<Basis, MixedSpace0, MixedSpace1>::MatrixType MatrixType;
+
+protected:
+    MixedGFEAssembler<Basis, MixedSpace0, MixedSpace1>* mixedAssembler_;
+
+public:
+    const ScalarBasis& basis_;
+
+    /** \brief Constructor for a given grid */
+    GeodesicFEAssemblerWrapper(MixedGFEAssembler<Basis, MixedSpace0, MixedSpace1>* mixedAssembler, ScalarBasis& basis)
+        : mixedAssembler_(mixedAssembler),
+          basis_(basis)
+    {
+        hessianMixed_ = std::make_unique<MatrixType>();
+        // The two spaces from the mixed version need to have the same embeddedDim as the Target Space
+        assert(MixedSpace0::embeddedDim + MixedSpace1::embeddedDim == TargetSpace::embeddedDim);
+        assert(blocksize0 + blocksize1 == blocksize);
+    }
+
+    /** \brief Assemble the tangent stiffness matrix and the functional gradient together
+     *
+     * This is more efficient than computing them separately, because you need the gradient
+     * anyway to compute the Riemannian Hessian.
+     */
+    virtual void assembleGradientAndHessian(const std::vector<TargetSpace>& sol,
+                                            Dune::BlockVector<Dune::FieldVector<double, blocksize> >& gradient,
+                                            Dune::BCRSMatrix<MatrixBlock>& hessian,
+                                            bool computeOccupationPattern=true) const;
+
+    /** \brief Assemble the gradient */
+    //virtual void assembleGradient(const std::vector<TargetSpace>& sol,
+    //                      Dune::BlockVector<Dune::FieldVector<double, blocksize> >& grad) const;
+
+    /** \brief Compute the energy of a deformation state */
+    virtual double computeEnergy(const std::vector<TargetSpace>& sol) const;
+
+    /** \brief Get the occupation structure of the Hessian */
+    virtual void getNeighborsPerVertex(Dune::MatrixIndexSet& nb) const;
+
+private:
+    Dune::TupleVector<std::vector<MixedSpace0>,std::vector<MixedSpace1>> splitVector(const std::vector<TargetSpace>& sol) const;
+    std::unique_ptr<MatrixType> hessianMixed_;
+}; // end class
+
+template <class Basis, class ScalarBasis, class TargetSpace, class MixedSpace0, class MixedSpace1>
+Dune::TupleVector<std::vector<MixedSpace0>,std::vector<MixedSpace1>> GeodesicFEAssemblerWrapper<Basis, ScalarBasis, TargetSpace,MixedSpace0,MixedSpace1>::
+splitVector(const std::vector<TargetSpace>& sol) const {
+    using namespace Dune::TypeTree::Indices;
+    // Split the solution into the Deformation and the Rotational part
+    auto n = basis_.size();
+    assert (sol.size() == n);
+    Dune::TupleVector<std::vector<MixedSpace0>,std::vector<MixedSpace1>> solutionSplit;
+    solutionSplit[_0].resize(n);
+    solutionSplit[_1].resize(n);
+    for (int i = 0; i < n; i++) {
+        solutionSplit[_0][i] = sol[i].r; // Deformation part
+        solutionSplit[_1][i] = sol[i].q; // Rotational part
+    }
+    return solutionSplit;
+}
+
+template <class Basis, class ScalarBasis, class TargetSpace, class MixedSpace0, class MixedSpace1>
+void GeodesicFEAssemblerWrapper<Basis, ScalarBasis, TargetSpace,MixedSpace0,MixedSpace1>::
+getNeighborsPerVertex(Dune::MatrixIndexSet& nb) const
+{
+    auto n = basis_.size();
+    nb.resize(n, n);
+    //Retrieve occupation structure for the mixed space and convert it to the non-mixed space
+    //In the mixed space, each index set is for one part of the composite basis
+    //So: nb00 is for the displacement part, nb11 is for the rotation part and nb01 and nb10 (where nb01^T = nb10) is for the coupling
+    Dune::MatrixIndexSet nb00, nb01, nb10, nb11;
+    mixedAssembler_->getMatrixPattern(nb00, nb01, nb10, nb11);
+    auto size0 = nb00.rows();
+    auto size1 = nb11.rows();
+    assert(size0 == size1);
+    assert(size0 == n);
+    //After checking if the sizes match, we can just copy over the occupation pattern
+    //as all occupation patterns work on the same basis combination, so they are all equal
+    nb = nb00;
+}
+
+template <class Basis, class ScalarBasis, class TargetSpace, class MixedSpace0, class MixedSpace1>
+void GeodesicFEAssemblerWrapper<Basis, ScalarBasis, TargetSpace,MixedSpace0,MixedSpace1>::
+assembleGradientAndHessian(const std::vector<TargetSpace>& sol,
+                           Dune::BlockVector<Dune::FieldVector<double, blocksize> >& gradient,
+                           Dune::BCRSMatrix<MatrixBlock>& hessian,
+                           bool computeOccupationPattern) const
+{
+    using namespace Dune::TypeTree::Indices;
+    auto n = basis_.size();
+
+    // Get a split up version of the input
+    auto solutionSplit = splitVector(sol);
+
+    // Define the Matrix and the Gradient in Block Stucture
+    Dune::BlockVector<Dune::FieldVector<double, blocksize0> > gradient0(n);
+    Dune::BlockVector<Dune::FieldVector<double, blocksize1> > gradient1(n);
+    
+    if (computeOccupationPattern) {
+        Dune::MatrixIndexSet neighborsPerVertex;
+        getNeighborsPerVertex(neighborsPerVertex);
+        neighborsPerVertex.exportIdx((*hessianMixed_)[_0][_0]);
+        neighborsPerVertex.exportIdx((*hessianMixed_)[_0][_1]);
+        neighborsPerVertex.exportIdx((*hessianMixed_)[_1][_0]);
+        neighborsPerVertex.exportIdx((*hessianMixed_)[_1][_1]);
+        neighborsPerVertex.exportIdx(hessian);
+    }
+
+    *hessianMixed_ = 0;
+    mixedAssembler_->assembleGradientAndHessian(solutionSplit[_0], solutionSplit[_1], gradient0, gradient1, *hessianMixed_, false);
+
+    // Transform gradient and hessian back to the non-mixed structure
+    hessian = 0;
+    gradient.resize(n);
+    gradient = 0;
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < blocksize0 + blocksize1; j++)
+            gradient[i][j] = j < blocksize0 ? gradient0[i][j] : gradient1[i][j - blocksize0];
+    }
+
+    // All 4 matrices are nxn;
+    // Each FieldMatrix in (*hessianMixed_)[_0][_0] is blocksize0 x blocksize0
+    // Each FieldMatrix in (*hessianMixed_)[_1][_0] is blocksize1 x blocksize0
+    // Each FieldMatrix in (*hessianMixed_)[_0][_1] is blocksize0 x blocksize1
+    // Each FieldMatrix in (*hessianMixed_)[_1][_1] is blocksize1 x blocksize1
+    // The hessian will then be a nxn matrix where each FieldMatrix is (blocksize0+blocksize1)x(blocksize0+blocksize1)
+    
+    for (size_t l = 0; l < blocksize0; l++) {
+        // Extract Upper Left Block of mixed matrix
+        for (auto rowIt = (*hessianMixed_)[_0][_0].begin(); rowIt != (*hessianMixed_)[_0][_0].end(); ++rowIt)
+            for (auto colIt = rowIt->begin(); colIt != rowIt->end(); ++colIt)
+                for(size_t k = 0; k < blocksize0; k++)
+                    hessian[rowIt.index()][colIt.index()][k][l] = (*colIt)[k][l];
+        // Extract Lower Left Block of mixed matrix
+        for (auto rowIt = (*hessianMixed_)[_1][_0].begin(); rowIt != (*hessianMixed_)[_1][_0].end(); ++rowIt)
+            for (auto colIt = rowIt->begin(); colIt != rowIt->end(); ++colIt)
+                for(size_t k = 0; k < blocksize1; k++)
+                    hessian[rowIt.index()][colIt.index()][k + blocksize0][l] = (*colIt)[k][l];
+    }
+    for (size_t l = 0; l < blocksize1; l++) {
+        // Extract Upper Right Block of mixed matrix
+        for (auto rowIt = (*hessianMixed_)[_0][_1].begin(); rowIt != (*hessianMixed_)[_0][_1].end(); ++rowIt)
+            for (auto colIt = rowIt->begin(); colIt != rowIt->end(); ++colIt)
+                for(size_t k = 0; k < blocksize0; k++)
+                        hessian[rowIt.index()][colIt.index()][k][l + blocksize0] = (*colIt)[k][l];
+        // Extract Lower Right Block of mixed matrix
+        for (auto rowIt = (*hessianMixed_)[_1][_1].begin(); rowIt != (*hessianMixed_)[_1][_1].end(); ++rowIt)
+            for (auto colIt = rowIt->begin(); colIt != rowIt->end(); ++colIt)
+                for(size_t k = 0; k < blocksize1; k++)
+                    hessian[rowIt.index()][colIt.index()][k + blocksize0][l + blocksize0] = (*colIt)[k][l];
+    }
+}
+
+/*template <class Basis, class ScalarBasis, class TargetSpace, class MixedSpace0, class MixedSpace1>
+void GeodesicFEAssemblerWrapper<Basis, ScalarBasis, TargetSpace,MixedSpace0,MixedSpace1>::
+assembleGradient(const std::vector<TargetSpace>& sol,
+                 Dune::BlockVector<Dune::FieldVector<double, blocksize> >& grad) const
+{
+    // Transform gradient back to the non-mixed structure
+    gradient.resize(n);
+    gradient = 0;
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < blocksize0 + blocksize1; j++)
+            gradient[i][j] = j < blocksize0 ? gradient0[i][j] : gradient1[i][j - blocksize0];
+    }
+}*/
+
+template <class Basis, class ScalarBasis, class TargetSpace, class MixedSpace0, class MixedSpace1>
+double GeodesicFEAssemblerWrapper<Basis, ScalarBasis, TargetSpace,MixedSpace0,MixedSpace1>::
+computeEnergy(const std::vector<TargetSpace>& sol) const
+{
+    using namespace Dune::TypeTree::Indices;
+    auto solutionSplit = splitVector(sol);
+    return mixedAssembler_->computeEnergy(solutionSplit[_0], solutionSplit[_1]);
+}
+#endif //GLOBAL_GEODESIC_FE_ASSEMBLER_WRAPPER_HH
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