atlas::mesh::MeshBuilder class
#include <atlas/mesh/MeshBuilder.h>

Construct a Mesh by importing external connectivity data.

Given a list of nodes and corresponding cell-to-node connectivity, sets up a Mesh. Not all Mesh fields are initialized, but enough are to build halos and construct a NodeColumns FunctionSpace.

Some limitations of the current implementation (but not inherent):

  • can only set up triangle and quad cells.
  • cannot import halos, i.e., cells owned by other MPI tasks; halos can still be subsequently computed by calling the BuildMesh action.
  • cannot import node-to-cell connectivity information.

The Mesh's Grid can be initialized via the call operator's optional config argument.

Base classes

template<typename LOCK>
class eckit::OwnedT<memory::detail::NoLock>

Public types

template<typename T>
using span = mdspan<T, dims<1>, layout_right>
template<typename T>
using strided_span = mdspan<T, dims<1>, layout_stride>

Constructors, destructors, conversion operators

MeshBuilder(const eckit::Configuration& = util::NoConfig())

Public functions

auto operator()(size_t nb_nodes, const double lon[], const double lat[], const int ghost[], const gidx_t global_index[], const idx_t remote_index[], const idx_t remote_index_base, const int partition[], size_t nb_triags, const gidx_t triag_nodes_global[], const gidx_t triag_global_index[], size_t nb_quads, const gidx_t quad_nodes_global[], const gidx_t quad_global_index[], const eckit::Configuration& config = util::NoConfig()) const -> Mesh
C-interface to construct a Mesh from external connectivity data.
auto operator()(size_t nb_nodes, const gidx_t global_index[], const double lon[], const double lat[], const int ghost[], const int partition[], const idx_t remote_index[], const idx_t remote_index_base, size_t nb_triags, const gidx_t triag_nodes_global[], const gidx_t triag_global_index[], size_t nb_quads, const gidx_t quad_nodes_global[], const gidx_t quad_global_index[], gidx_t global_index_base, const eckit::Configuration& config = util::NoConfig()) const -> Mesh
auto operator()(size_t nb_nodes, const gidx_t global_index[], const double x[], const double y[], size_t xstride, size_t ystride, const double lon[], const double lat[], size_t lonstride, size_t latstride, const int ghost[], const int partition[], const idx_t remote_index[], const idx_t remote_index_base, size_t nb_triags, const gidx_t triag_global_index[], const gidx_t triag_nodes_global[], size_t nb_quads, const gidx_t quad_global_index[], const gidx_t quad_nodes_global[], const eckit::Configuration& config = util::NoConfig()) const -> Mesh
auto operator()(size_t nb_nodes, const gidx_t global_index[], const double x[], const double y[], size_t xstride, size_t ystride, const double lon[], const double lat[], size_t lonstride, size_t latstride, const int ghost[], const int partition[], const idx_t remote_index[], const idx_t remote_index_base, size_t nb_triags, const gidx_t triag_global_index[], const gidx_t triag_nodes_global[], size_t nb_quads, const gidx_t quad_global_index[], const gidx_t quad_nodes_global[], gidx_t global_index_base, const eckit::Configuration& config = util::NoConfig()) const -> Mesh
auto operator()(span<const gidx_t> global_index, strided_span<const double> x, strided_span<const double> y, strided_span<const double> lon, strided_span<const double> lat, span<const int> ghost, span<const int> partition, span<const idx_t> remote_index, const idx_t remote_index_base, span<const gidx_t> triag_global_index, mdspan<const gidx_t, extents<size_t, dynamic_extent, 3>> triag_nodes_global, span<const gidx_t> quad_global_index, mdspan<const gidx_t, extents<size_t, dynamic_extent, 4>> quad_nodes_global, const gidx_t global_index_base, const eckit::Configuration& config = util::NoConfig()) const -> Mesh
auto operator()(const std::vector<double>& lons, const std::vector<double>& lats, const std::vector<int>& ghosts, const std::vector<gidx_t>& global_index, const std::vector<idx_t>& remote_index, const idx_t remote_index_base, const std::vector<int>& partitions, const std::vector<std::array<gidx_t, 3>>& triag_nodes_global, const std::vector<gidx_t>& triag_global_index, const std::vector<std::array<gidx_t, 4>>& quad_nodes_global, const std::vector<gidx_t>& quad_global_index, const eckit::Configuration& config = util::NoConfig()) const -> Mesh
C++-interface to construct a Mesh from external connectivity data.

Function documentation

Mesh atlas::mesh::MeshBuilder::operator()(size_t nb_nodes, const double lon[], const double lat[], const int ghost[], const gidx_t global_index[], const idx_t remote_index[], const idx_t remote_index_base, const int partition[], size_t nb_triags, const gidx_t triag_nodes_global[], const gidx_t triag_global_index[], size_t nb_quads, const gidx_t quad_nodes_global[], const gidx_t quad_global_index[], const eckit::Configuration& config = util::NoConfig()) const

C-interface to construct a Mesh from external connectivity data.

The inputs lons, lats, ghosts, global_indices, remote_indices, and partitions are vectors of size nb_nodes, ranging over the nodes locally owned by (or in the ghost nodes of) the MPI task. The global index is a uniform labeling of the nodes across all MPI tasks; the remote index is a remote_index_base-based vector index for the node on its owning task.

The tri/quad connectivities (boundary_nodes and global_indices) are vectors ranging over the cells owned by the MPI task. Each cell is defined by a list of nodes defining its boundary; note that each boundary node must be locally known (whether as an owned of ghost node on the MPI task), in other words, must be an element of the node global_indices. The boundary nodes are ordered node-varies-fastest, element-varies-slowest order. The cell global index is, here also, a uniform labeling over the of the cells across all MPI tasks.

The config argument can be used to

  • Request the Mesh's Grid to be constructed, usually from the config. If the Grid is either an UnstructuredGrid or a Structured grid, the validate bool option can be used to trigger a simple check that the grid is consistent with the lons/lats passed in to the MeshBuilder. In the special case where grid.type is unstructured and the grid.xy coordinates are not given, then the grid is constructed from the lons/lats passed to the MeshBuilder.
  • Select which MPI communicator to use.

Mesh atlas::mesh::MeshBuilder::operator()(const std::vector<double>& lons, const std::vector<double>& lats, const std::vector<int>& ghosts, const std::vector<gidx_t>& global_index, const std::vector<idx_t>& remote_index, const idx_t remote_index_base, const std::vector<int>& partitions, const std::vector<std::array<gidx_t, 3>>& triag_nodes_global, const std::vector<gidx_t>& triag_global_index, const std::vector<std::array<gidx_t, 4>>& quad_nodes_global, const std::vector<gidx_t>& quad_global_index, const eckit::Configuration& config = util::NoConfig()) const

C++-interface to construct a Mesh from external connectivity data.

Provides a wrapper to the C-interface using STL containers.