Now out of date. See the RTD DomainDecomposition description.
Notes about the various partitioning schemes. (*) is the default if METIS
is available, (-) if not.
cells are divided into rectangular, axis aligned, boxes, with
the given number of sides per axis. Needs one rectangular box
the cell grid (where each cell is a graph vertex with edges
to all neighbours) is split into similar sized connected regions by METIS.
in this version the vertices of the cell graph are weighted
by the particle counts. This aims to give similar numbers
of particles per rank.
the cells are considered as a 1D array and positions are picked
along it for each rank. These positions are then used as centres
in 3D and neighbouring cells are assigned to a rank using distance.
This method is guaranteed to work when we have more cells than ranks,
the other methods can fail when this criterion is close.
erm, do nothing, keeping fingers crossed (useful for testing)
Assign weights to the vertices and edges of the cell graph based
on the task weights associated with each cell and allow METIS to decide on
an optimal partition to share the cells between the ranks.
Similar to task_weights, except we only weight the vertices by the
cell particles counts.
Similar to task_weights, except we only use the task weights as edge weights.
Joins particle_weights and edge_task_weights, we have particle weights
for the graph vertices and task weights for the edges.