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# Copyright (C) 2020 Jørgen S. Dokken
#
# This file is part of DOLFINX_MPC
#
# SPDX-License-Identifier: MIT
import contextlib
from typing import List, Sequence
import dolfinx.cpp as _cpp
import dolfinx.fem as _fem
import ufl
from dolfinx.common import Timer
from petsc4py import PETSc as _PETSc
import dolfinx_mpc.cpp
from .multipointconstraint import MultiPointConstraint
def apply_lifting(b: _PETSc.Vec, form: List[_fem.FormMetaClass], bcs: List[List[_fem.DirichletBCMetaClass]],
constraint: MultiPointConstraint, x0: List[_PETSc.Vec] = [], scale: float = 1.0):
"""
Apply lifting to vector b, i.e.
.. math::
b <- b - scale * K^T (A_j (g_j - x0_j))
Parameters
----------
b
PETSc vector to assemble into
form
The linear form
bcs
List of Dirichlet boundary conditions
constraint
The multi point constraint
x0
List of vectors
scale
Scaling for lifting
Returns
-------
PETSc.Vec
The assembled linear form
"""
t = Timer("~MPC: Apply lifting (C++)")
with contextlib.ExitStack() as stack:
x0 = [stack.enter_context(x.localForm()) for x in x0]
x0_r = [x.array_r for x in x0]
b_local = stack.enter_context(b.localForm())
dolfinx_mpc.cpp.mpc.apply_lifting(b_local.array_w, form,
bcs, x0_r, scale, constraint._cpp_object)
t.stop()
def assemble_vector(form: ufl.form.Form, constraint: MultiPointConstraint,
b: _PETSc.Vec = None) -> _PETSc.Vec:
"""
Assemble a linear form into vector b with corresponding multi point constraint
Parameters
----------
form
The linear form
constraint
The multi point constraint
b
PETSc vector to assemble into (optional)
Returns
-------
PETSc.Vec
The assembled linear form
"""
if b is None:
b = _cpp.la.petsc.create_vector(constraint.function_space.dofmap.index_map,
constraint.function_space.dofmap.index_map_bs)
t = Timer("~MPC: Assemble vector (C++)")
with b.localForm() as b_local:
b_local.set(0.0)
dolfinx_mpc.cpp.mpc.assemble_vector(b_local, form, constraint._cpp_object)
t.stop()
return b
def create_vector_nest(
L: Sequence[_fem.FormMetaClass],
constraints: Sequence[MultiPointConstraint]) -> _PETSc.Vec:
"""
Create a PETSc vector of type "nest" appropriate for the provided multi
point constraints
Parameters
----------
L
A sequence of linear forms
constraints
An ordered list of multi point constraints
Returns
-------
PETSc.Vec
A PETSc vector of type "nest"
"""
assert len(constraints) == len(L)
maps = [(constraint.function_space.dofmap.index_map,
constraint.function_space.dofmap.index_map_bs)
for constraint in constraints]
return _cpp.fem.petsc.create_vector_nest(maps)
def assemble_vector_nest(
b: _PETSc.Vec,
L: Sequence[_fem.FormMetaClass],
constraints: Sequence[MultiPointConstraint]):
"""
Assemble a linear form into a PETSc vector of type "nest"
Parameters
----------
b
A PETSc vector of type "nest"
L
A sequence of linear forms
constraints
An ordered list of multi point constraints
"""
assert len(constraints) == len(L)
assert b.getType() == "nest"
b_sub_vecs = b.getNestSubVecs()
for i, L_row in enumerate(L):
assemble_vector(L_row, constraints[i], b=b_sub_vecs[i])
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