def __init__(self, name, terms):
Struct.__init__(self, name=name)
if isinstance(terms, Term): # A single term.
terms = Terms([terms])
self.terms = terms
self.terms.setup()
def from_desc(name, desc, variables, regions, materials, integrals, caches=None, user=None):
term_descs = parse_definition(desc)
terms = Terms.from_desc(term_descs, regions, integrals)
terms.setup()
terms.assign_args(variables, materials, user)
obj = Equation(name, terms, caches=caches)
return obj
def from_desc(name, desc, variables, regions, materials, integrals,
user=None):
term_descs = parse_definition(desc)
terms = Terms.from_desc(term_descs, regions, integrals)
terms.setup()
terms.assign_args(variables, materials, user)
obj = Equation(name, terms)
return obj
def create_subequations(self, var_names, known_var_names=None):
"""
Create sub-equations containing only terms with the given virtual
variables.
Parameters
----------
var_names : list
The list of names of virtual variables.
known_var_names : list
The list of names of (already) known state variables.
Returns
-------
subequations : Equations instance
The sub-equations.
"""
from sfepy.fem import FieldVariable
known_var_names = get_default(known_var_names, [])
objs = []
for iv, var_name in enumerate(var_names):
terms = [
term.copy(name=term.name) for eq in self for term in eq.terms
if term.get_virtual_name() == var_name
]
# Make parameter variables from known state variables in terms
# arguments.
for known_name in known_var_names:
for term in terms:
if known_name in term.arg_names:
ii = term.arg_names.index(known_name)
state = self.variables[known_name]
par = FieldVariable(known_name,
'parameter',
state.field,
state.n_components,
primary_var_name='(set-to-None)')
term.args[ii] = par
term._kwargs[known_name] = par
par.set_data(state())
new_terms = Terms(terms)
objs.append(Equation('eq_%d' % iv, new_terms))
subequations = Equations(objs)
return subequations
def get_problem(u_field, v_field, calc_stiffness, calc_prestress, delta_x):
"""Get the problem
Args:
u_field: the displacement field
v_field: the test function field
calc_stiffness: a functioin to calcuate the stiffness tensor
calc_prestress: a function to calculate the prestress tensor
delta_x: the mesh spacing
Returns:
the Sfepy problem
"""
return pipe(
get_terms(u_field, v_field, calc_stiffness, calc_prestress),
lambda x: Equation("balance_of_forces", Terms([x[0], x[1]])),
lambda x: Problem("elasticity", equations=Equations([x])),
do(lambda x: x.time_update(ebcs=get_bcs(v_field.field.region.domain, delta_x))),
do(lambda x: x.set_solver(get_nls(x.get_evaluator()))),
)
def from_desc(name,
desc,
variables,
regions,
materials,
integrals,
user=None,
eterm_options=None):
term_descs = parse_definition(desc)
terms = Terms.from_desc(term_descs, regions, integrals)
terms.setup()
terms.assign_args(variables, materials, user)
if eterm_options is not None:
for term in terms:
if isinstance(term, ETermBase):
term.set_verbosity(eterm_options.get('verbosity', 0))
term.set_backend(**eterm_options.get('backend_args', {}))
obj = Equation(name, terms)
return obj