def assemble_system(A_form,
b_form,
bcs=None,
x0=None,
A_coefficients=None,
b_coefficients=None,
A_function_spaces=None,
b_function_spaces=None,
cell_domains=None,
exterior_facet_domains=None,
interior_facet_domains=None,
reset_sparsity=True,
add_values=False,
finalize_tensor=True,
keep_diagonal=False,
A_tensor=None,
b_tensor=None,
backend=None,
form_compiler_parameters=None):
"""
Assemble form(s) and apply any given boundary conditions in a
symmetric fashion and return tensor(s).
The standard application of boundary conditions does not
necessarily preserve the symmetry of the assembled matrix. In
order to perserve symmetry in a system of equations with boundary
conditions, one may use the alternative assemble_system instead of
multiple calls to :py:func:`assemble
<dolfin.fem.assembling.assemble>`.
*Examples of usage*
For instance, the statements
.. code-block:: python
A = assemble(a)
b = assemble(L)
bc.apply(A, b)
can alternatively be carried out by
.. code-block:: python
A, b = assemble_system(a, L, bc)
The statement above is valid even if ``bc`` is a list of
:py:class:`DirichletBC <dolfin.fem.bcs.DirichletBC>`
instances. For more info and options, see :py:func:`assemble
<dolfin.fem.assembling.assemble>`.
"""
# Extract subdomains
subdomains = {
"cell": cell_domains,
"exterior_facet": exterior_facet_domains,
"interior_facet": interior_facet_domains
}
# Wrap forms
A_dolfin_form = Form(A_form, A_function_spaces, A_coefficients, subdomains,
form_compiler_parameters)
b_dolfin_form = Form(b_form, b_function_spaces, b_coefficients, subdomains,
form_compiler_parameters)
# Create tensors
A_tensor = _create_tensor(A_form, A_dolfin_form.rank(), backend, A_tensor)
b_tensor = _create_tensor(b_form, b_dolfin_form.rank(), backend, b_tensor)
# Extract domains
cell_domains, exterior_facet_domains, interior_facet_domains = \
_extract_domains(A_dolfin_form.mesh(),
cell_domains,
exterior_facet_domains,
interior_facet_domains)
# Attach domains to form (from Mesh, in other cases form already
# has domain data attached)
if cell_domains is not None:
A_dolfin_form.set_cell_domains(cell_domains)
b_dolfin_form.set_cell_domains(cell_domains)
if interior_facet_domains is not None:
A_dolfin_form.set_interior_facet_domains(interior_facet_domains)
b_dolfin_form.set_interior_facet_domains(interior_facet_domains)
if exterior_facet_domains is not None:
A_dolfin_form.set_exterior_facet_domains(exterior_facet_domains)
b_dolfin_form.set_exterior_facet_domains(exterior_facet_domains)
# Check bcs
bcs = _wrap_in_list(bcs, 'bcs', cpp.DirichletBC)
# Call C++ assemble function
assembler = cpp.SystemAssembler(A_dolfin_form, b_dolfin_form, bcs)
assembler.reset_sparsity = reset_sparsity
assembler.add_values = add_values
assembler.finalize_tensor = finalize_tensor
assembler.keep_diagonal = keep_diagonal
if x0 is not None:
assembler.assemble(A_tensor, b_tensor, x0)
else:
assembler.assemble(A_tensor, b_tensor)
return A_tensor, b_tensor
def assemble_system(A_form,
b_form,
bcs=None,
x0=None,
form_compiler_parameters=None,
add_values=False,
finalize_tensor=True,
keep_diagonal=False,
A_tensor=None,
b_tensor=None,
backend=None):
"""
Assemble form(s) and apply any given boundary conditions in a
symmetric fashion and return tensor(s).
The standard application of boundary conditions does not
necessarily preserve the symmetry of the assembled matrix. In
order to perserve symmetry in a system of equations with boundary
conditions, one may use the alternative assemble_system instead of
multiple calls to :py:func:`assemble
<dolfin.fem.assembling.assemble>`.
*Examples of usage*
For instance, the statements
.. code-block:: python
A = assemble(a)
b = assemble(L)
bc.apply(A, b)
can alternatively be carried out by
.. code-block:: python
A, b = assemble_system(a, L, bc)
The statement above is valid even if ``bc`` is a list of
:py:class:`DirichletBC <dolfin.fem.bcs.DirichletBC>`
instances. For more info and options, see :py:func:`assemble
<dolfin.fem.assembling.assemble>`.
"""
# Create dolfin Form objects referencing all data needed by assembler
A_dolfin_form = _create_dolfin_form(A_form, form_compiler_parameters)
b_dolfin_form = _create_dolfin_form(b_form, form_compiler_parameters)
# Create tensors
A_tensor = _create_tensor(A_form, A_dolfin_form.rank(), backend, A_tensor)
b_tensor = _create_tensor(b_form, b_dolfin_form.rank(), backend, b_tensor)
# Check bcs
bcs = _wrap_in_list(bcs, 'bcs', cpp.DirichletBC)
# Call C++ assemble function
assembler = cpp.SystemAssembler(A_dolfin_form, b_dolfin_form, bcs)
assembler.add_values = add_values
assembler.finalize_tensor = finalize_tensor
assembler.keep_diagonal = keep_diagonal
if x0 is not None:
assembler.assemble(A_tensor, b_tensor, x0)
else:
assembler.assemble(A_tensor, b_tensor)
return A_tensor, b_tensor