petsc4py.PETSc.DMComposite#

class petsc4py.PETSc.DMComposite#

Bases: DM

A DM object that is used to manage data for a collection of DMs.

Methods Summary

`addDM`(dm, *args)	Add a DM vector to the composite.
`create`([comm])	Create a composite object.
`gather`(gvec, imode, lvecs)	Gather split local vectors into a coupled global vector.
`getAccess`(gvec[, locs])	Get access to the individual vectors from the global vector.
`getEntries`()	Return sub-DMs contained in the composite.
`getGlobalISs`()	Return the index sets for each composed object in the composite.
`getLGMaps`()	Return a local-to-global mapping for each DM in the composite.
`getLocalISs`()	Return index sets for each component of a composite local vector.
`getNumber`()	Get number of sub-DMs contained in the composite.
`scatter`(gvec, lvecs)	Scatter coupled global vector into split local vectors.

Methods Documentation

addDM(dm, *args)#

Add a DM vector to the composite.

Collective.

Parameters:

dm (DM) – The DM object.
*args (DM) – Additional DM objects.

Return type:

None

See also

DMCompositeAddDM

Source code at petsc4py/PETSc/DMComposite.pyx:27

create(comm=None)#

Create a composite object.

Collective.

Parameters:: comm (Comm | None) – MPI communicator, defaults to Sys.getDefaultComm.
Return type:: Self

See also

DMCompositeCreate

Source code at petsc4py/PETSc/DMComposite.pyx:6

gather(gvec, imode, lvecs)#

Gather split local vectors into a coupled global vector.

Collective.

Parameters:

gvec (Vec) – The global vector.
imode (InsertModeSpec) – The insertion mode.
lvecs (Sequence[Vec]) – The individual sequential vectors.

Return type:

None

See also

scatter, DMCompositeGatherArray

Source code at petsc4py/PETSc/DMComposite.pyx:114

getAccess(gvec, locs=None)#

Get access to the individual vectors from the global vector.

Not collective.

Use via The with statement context manager (PEP 343).

Parameters:

gvec (Vec) – The global vector.
locs (Sequence[int] | None) – Indices of vectors wanted, or None to get all vectors.

Return type:

Any

Source code at petsc4py/PETSc/DMComposite.pyx:218

getEntries()#

Return sub-DMs contained in the composite.

Not collective.

See also

DMCompositeGetEntriesArray

Source code at petsc4py/PETSc/DMComposite.pyx:65

Return type:: list[DM]

getGlobalISs()#

Return the index sets for each composed object in the composite.

Collective.

These could be used to extract a subset of vector entries for a “multi-physics” preconditioner.

Use getLocalISs for index sets in the packed local numbering, and getLGMaps for to map local sub-DM (including ghost) indices to packed global indices.

See also

DMCompositeGetGlobalISs

Source code at petsc4py/PETSc/DMComposite.pyx:142