From: Timo Heister Date: Tue, 13 Aug 2024 17:11:15 +0000 (-0400) Subject: step-37: use MatrixFreeTools::compute_diagonal() X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0b2c9c465969e5efe7f9e098f5b811d9d839148c;p=dealii.git step-37: use MatrixFreeTools::compute_diagonal() --- diff --git a/examples/step-37/step-37.cc b/examples/step-37/step-37.cc index 40a36faf86..be812ae91f 100644 --- a/examples/step-37/step-37.cc +++ b/examples/step-37/step-37.cc @@ -236,10 +236,7 @@ namespace Step37 const std::pair &cell_range) const; void local_compute_diagonal( - const MatrixFree &data, - LinearAlgebra::distributed::Vector &dst, - const unsigned int &dummy, - const std::pair &cell_range) const; + FEEvaluation &integrator) const; Table<2, VectorizedArray> coefficient; }; @@ -515,12 +512,10 @@ namespace Step37 // inverse_diagonal_entries of type DiagonalMatrix in the base class // MatrixFreeOperators::Base. This member is a shared pointer that we first // need to initialize and then get the vector representing the diagonal - // entries in the matrix. As to the actual diagonal computation, we again - // use the cell_loop infrastructure of MatrixFree to invoke a local worker - // routine called local_compute_diagonal(). Since we will only write into a - // vector but not have any source vector, we put a dummy argument of type - // unsigned int in place of the source vector to confirm with the - // cell_loop interface. After the loop, we need to set the vector entries + // entries in the matrix. As to the actual diagonal computation, we could + // manually write a cell_loop and invoke a local worker that applies all unit + // vectors on each cell. Instead, we use MatrixFreeTools::compute_diagonal() + // to do this for us. Afterwards, we need to set the vector entries // subject to Dirichlet boundary conditions to one (either those on the // boundary described by the AffineConstraints object inside MatrixFree or // the indices at the interface between different grid levels in adaptive @@ -531,8 +526,7 @@ namespace Step37 // form required by the Chebyshev smoother based on the Jacobi iteration. In // the loop, we assert that all entries are non-zero, because they should // either have obtained a positive contribution from integrals or be - // constrained and treated by @p set_constrained_entries_to_one() following - // cell_loop. + // constrained and treated by @p set_constrained_entries_to_one(). template void LaplaceOperator::compute_diagonal() { @@ -541,11 +535,11 @@ namespace Step37 LinearAlgebra::distributed::Vector &inverse_diagonal = this->inverse_diagonal_entries->get_vector(); this->data->initialize_dof_vector(inverse_diagonal); - unsigned int dummy = 0; - this->data->cell_loop(&LaplaceOperator::local_compute_diagonal, - this, - inverse_diagonal, - dummy); + + MatrixFreeTools::compute_diagonal(*this->data, + inverse_diagonal, + &LaplaceOperator::local_compute_diagonal, + this); this->set_constrained_entries_to_one(inverse_diagonal); @@ -609,38 +603,17 @@ namespace Step37 // level matrices where no hanging node constraints appear. template void LaplaceOperator::local_compute_diagonal( - const MatrixFree &data, - LinearAlgebra::distributed::Vector &dst, - const unsigned int &, - const std::pair &cell_range) const + FEEvaluation &phi) const { - FEEvaluation phi(data); + const unsigned int cell = phi.get_current_cell_index(); - AlignedVector> diagonal(phi.dofs_per_cell); + phi.evaluate(EvaluationFlags::gradients); - for (unsigned int cell = cell_range.first; cell < cell_range.second; ++cell) + for (const unsigned int q : phi.quadrature_point_indices()) { - AssertDimension(coefficient.size(0), data.n_cell_batches()); - AssertDimension(coefficient.size(1), phi.n_q_points); - - phi.reinit(cell); - for (unsigned int i = 0; i < phi.dofs_per_cell; ++i) - { - for (unsigned int j = 0; j < phi.dofs_per_cell; ++j) - phi.submit_dof_value(VectorizedArray(), j); - phi.submit_dof_value(make_vectorized_array(1.), i); - - phi.evaluate(EvaluationFlags::gradients); - for (const unsigned int q : phi.quadrature_point_indices()) - phi.submit_gradient(coefficient(cell, q) * phi.get_gradient(q), - q); - phi.integrate(EvaluationFlags::gradients); - diagonal[i] = phi.get_dof_value(i); - } - for (unsigned int i = 0; i < phi.dofs_per_cell; ++i) - phi.submit_dof_value(diagonal[i], i); - phi.distribute_local_to_global(dst); + phi.submit_gradient(coefficient(cell, q) * phi.get_gradient(q), q); } + phi.integrate(EvaluationFlags::gradients); }