petsc4py.PETSc.Scatter#

class petsc4py.PETSc.Scatter#

Bases: Object

Scatter object.

The object used to perform data movement between vectors. Scatter is described in the PETSc manual.

See also

Vec, SF, VecScatter

Enumerations

`Mode`	Scatter mode.
`Type`	Scatter type.

Methods Summary

`begin`(vec_from, vec_to[, addv, mode])	Begin a generalized scatter from one vector into another.
`copy`()	Return a copy of the scatter.
`create`(vec_from, is_from, vec_to, is_to)	Create a scatter object.
`destroy`()	Destroy the scatter.
`end`(vec_from, vec_to[, addv, mode])	Complete a generalized scatter from one vector into another.
`getType`()	Return the type of the scatter.
`scatter`(vec_from, vec_to[, addv, mode])	Perform a generalized scatter from one vector into another.
`setFromOptions`()	Configure the scatter from the options database.
`setType`(scatter_type)	Set the type of the scatter.
`setUp`()	Set up the internal data structures for using the scatter.
`toAll`(vec)	Create a scatter that communicates a vector to all sharing processes.
`toZero`(vec)	Create a scatter that communicates a vector to rank zero.
`view`([viewer])	View the scatter.

Methods Documentation

begin(vec_from, vec_to, addv=None, mode=None)#

Begin a generalized scatter from one vector into another.

Collective.

This call has to be concluded with a call to end. For additional details on the Parameters, see scatter.

See also

create, end, VecScatterBegin

Source code at petsc4py/PETSc/Scatter.pyx:263

Parameters:

vec_from (Vec) –
vec_to (Vec) –
addv (InsertModeSpec) –
mode (ScatterModeSpec) –

Return type:

None

copy()#

Return a copy of the scatter.

Source code at petsc4py/PETSc/Scatter.pyx:200

Return type:: Scatter

create(vec_from, is_from, vec_to, is_to)#

Create a scatter object.

Collective.

Parameters:

vec_from (Vec) – Representative vector from which to scatter the data.
is_from (IS) – Indices of vec_from to scatter. If None, use all indices.
vec_to (Vec) – Representative vector to which scatter the data.
is_to (IS) – Indices of vec_to where to receive. If None, use all indices.

Return type:

Self

Examples

The scatter object can be used to repeatedly perform data movement. It is the PETSc equivalent of NumPy-like indexing and slicing, with support for parallel communications:

>>> revmode = PETSc.Scatter.Mode.REVERSE
>>> v1 = PETSc.Vec().createWithArray([1, 2, 3])
>>> v2 = PETSc.Vec().createWithArray([0, 0, 0])
>>> sct = PETSc.Scatter().create(v1,None,v2,None)
>>> sct.scatter(v1,v2) # v2[:] = v1[:]
>>> sct.scatter(v2,v1,mode=revmode) # v1[:] = v2[:]

>>> revmode = PETSc.Scatter.Mode.REVERSE
>>> v1 = PETSc.Vec().createWithArray([1, 2, 3, 4])
>>> v2 = PETSc.Vec().createWithArray([0, 0])
>>> is1 = PETSc.IS().createStride(2, 3, -2)
>>> sct = PETSc.Scatter().create(v1,is1,v2,None)
>>> sct.scatter(v1,v2) # v2[:] = v1[3:0:-2]
>>> sct.scatter(v2,v1,mode=revmode) # v1[3:0:-2] = v2[:]

See also

IS, VecScatterCreate

Source code at petsc4py/PETSc/Scatter.pyx:90

destroy()#

Destroy the scatter.

Collective.

See also

VecScatterDestroy

Source code at petsc4py/PETSc/Scatter.pyx:77

Return type:: Self

end(vec_from, vec_to, addv=None, mode=None)#

Complete a generalized scatter from one vector into another.

Collective.

This call has to be preceded by a call to begin. For additional details on the Parameters, see scatter.

See also

create, begin, VecScatterEnd

Source code at petsc4py/PETSc/Scatter.pyx:287

Parameters:

vec_from (Vec) –
vec_to (Vec) –
addv (InsertModeSpec) –
mode (ScatterModeSpec) –

Return type:

None

getType()#

Return the type of the scatter.

Not collective.

See also

setType, VecScatterGetType

Source code at petsc4py/PETSc/Scatter.pyx:161

Return type:: str

scatter(vec_from, vec_to, addv=None, mode=None)#

Perform a generalized scatter from one vector into another.

Collective.

Parameters:

vec_from (Vec) – The source vector.
vec_to (Vec) – The destination vector.
addv (InsertModeSpec) – Insertion mode.
mode (ScatterModeSpec) – Scatter mode.

Return type:

None

Source code at petsc4py/PETSc/Scatter.pyx:311

setFromOptions()#

Configure the scatter from the options database.

Collective.

Source code at petsc4py/PETSc/Scatter.pyx:175

Return type:: None

setType(scatter_type)#

Set the type of the scatter.

Logically collective.

See also

getType, VecScatterSetType

Source code at petsc4py/PETSc/Scatter.pyx:147

Parameters:: scatter_type (Type | str) –
Return type:: None

setUp()#

Set up the internal data structures for using the scatter.

Collective.

See also

VecScatterSetUp

Source code at petsc4py/PETSc/Scatter.pyx:187

Return type:: Self

classmethod toAll(vec)#

Create a scatter that communicates a vector to all sharing processes.

Collective.

Parameters:: vec (Vec) – The vector to scatter from.
Return type:: tuple[Scatter, Vec]

Notes

The created scatter will have the same communicator of vec. The method also returns an output vector of appropriate size to contain the result of the operation.

See also

toZero, VecScatterCreateToAll

Source code at petsc4py/PETSc/Scatter.pyx:206

classmethod toZero(vec)#

Create a scatter that communicates a vector to rank zero.

Collective.

Parameters:: vec (Vec) – The vector to scatter from.
Return type:: tuple[Scatter, Vec]

Notes

The created scatter will have the same communicator of vec. The method also returns an output vector of appropriate size to contain the result of the operation.

See also

toAll, VecScatterCreateToZero

Source code at petsc4py/PETSc/Scatter.pyx:234

view(viewer=None)#

View the scatter.

Collective.