Add symmetry treatment for DiscreteFunctionP0Vector of TinyVector

src/scheme/PolynomialReconstruction.cpp

@@ -1085,10 +1085,32 @@ PolynomialReconstruction::_build(
 
                   for (size_t i_symmetry = 0; i_symmetry < stencil_array.symmetryBoundaryStencilArrayList().size();
                        ++i_symmetry) {
+                    if constexpr (DataType::Dimension == MeshType::Dimension) {
                       auto& ghost_stencil = stencil_array.symmetryBoundaryStencilArrayList()[i_symmetry].stencilArray();
                       auto ghost_cell_list = ghost_stencil[cell_j_id];
-                    if (ghost_cell_list.size() > 0) {
-                      throw NotImplementedError("TinyVector symmetries for reconstruction of DiscreteFunctionP0Vector");
+
+                      const Rd& normal = symmetry_normal_list[i_symmetry];
+
+                      for (size_t i = 0; i < ghost_cell_list.size(); ++i, ++index) {
+                        const CellId cell_i_id = ghost_cell_list[i];
+
+                        for (size_t l = 0; l < qj_vector.size(); ++l) {
+                          const DataType& qj    = qj_vector[l];
+                          const DataType& qi    = discrete_function[cell_i_id][l];
+                          const DataType& qi_qj = symmetrize_vector(normal, qi) - qj;
+                          for (size_t kB = column_begin + l * DataType::Dimension, k = 0; k < DataType::Dimension;
+                               ++k, ++kB) {
+                            B(index, kB) = qi_qj[k];
+                          }
+                        }
+                      }
+                    } else {
+                      // LCOV_EXCL_START
+                      std::stringstream error_msg;
+                      error_msg << "cannot symmetrize vectors of dimension " << DataType::Dimension
+                                << " using a mesh of dimension " << MeshType::Dimension;
+                      throw UnexpectedError(error_msg.str());
+                      // LCOV_EXCL_STOP
                     }
                   }
                 } else if constexpr (is_tiny_matrix_v<DataType>) {

tests/CMakeLists.txt

@@ -275,7 +275,7 @@ add_executable (mpi_unit_tests
   test_OFStream.cpp
   test_ParallelChecker_read.cpp
   test_Partitioner.cpp
-  test_PolynomialReconstruction.cpp
+  test_PolynomialReconstruction_degree_1.cpp
   test_PolynomialReconstructionDescriptor.cpp
   test_RandomEngine.cpp
   test_StencilBuilder_cell2cell.cpp