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rGOOSEFEM/include/GooseFEM/MatrixDiagonal.h
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MatrixDiagonal.h
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/*
(c - GPLv3) T.W.J. de Geus (Tom) | tom@geus.me | www.geus.me | github.com/tdegeus/GooseFEM
*/
#ifndef GOOSEFEM_MATRIXDIAGONAL_H
#define GOOSEFEM_MATRIXDIAGONAL_H
#include "config.h"
namespace GooseFEM {
class MatrixDiagonal {
public:
// Constructors
MatrixDiagonal() = default;
MatrixDiagonal(const xt::xtensor<size_t, 2>& conn, const xt::xtensor<size_t, 2>& dofs);
// Dimensions
size_t nelem() const; // number of elements
size_t nne() const; // number of nodes per element
size_t nnode() const; // number of nodes
size_t ndim() const; // number of dimensions
size_t ndof() const; // number of DOFs
// DOF lists
xt::xtensor<size_t, 2> dofs() const; // DOFs
// Set matrix components
void set(const xt::xtensor<double, 1>& A);
// assemble from matrices stored per element [nelem, nne*ndim, nne*ndim]
// WARNING: ignores any off-diagonal terms
void assemble(const xt::xtensor<double, 3>& elemmat);
// Dot-product:
// b_i = A_ij * x_j
void dot(const xt::xtensor<double, 2>& x, xt::xtensor<double, 2>& b) const;
void dot(const xt::xtensor<double, 1>& x, xt::xtensor<double, 1>& b) const;
// Solve:
// x = A \ b
void solve(const xt::xtensor<double, 2>& b, xt::xtensor<double, 2>& x);
void solve(const xt::xtensor<double, 1>& b, xt::xtensor<double, 1>& x);
// Return matrix as diagonal matrix (column)
xt::xtensor<double, 1> AsDiagonal() const;
// Auto-allocation of the functions above
xt::xtensor<double, 2> Dot(const xt::xtensor<double, 2>& x) const;
xt::xtensor<double, 1> Dot(const xt::xtensor<double, 1>& x) const;
xt::xtensor<double, 2> Solve(const xt::xtensor<double, 2>& b);
xt::xtensor<double, 1> Solve(const xt::xtensor<double, 1>& b);
private:
// The diagonal matrix, and its inverse (re-used to solve different RHS)
xt::xtensor<double, 1> m_A;
xt::xtensor<double, 1> m_inv;
// Signal changes to data compare to the last inverse
bool m_factor = false;
// Bookkeeping
xt::xtensor<size_t, 2> m_conn; // connectivity [nelem, nne]
xt::xtensor<size_t, 2> m_dofs; // DOF-numbers per node [nnode, ndim]
// Dimensions
size_t m_nelem; // number of elements
size_t m_nne; // number of nodes per element
size_t m_nnode; // number of nodes
size_t m_ndim; // number of dimensions
size_t m_ndof; // number of DOFs
// Compute inverse (automatically evaluated by "solve")
void factorize();
};
} // namespace GooseFEM
#include "MatrixDiagonal.hpp"
#endif
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