Source code for ufl.integral

"""The Integral class."""

# Copyright (C) 2008-2016 Martin Sandve Aln├Žs
#
# This file is part of UFL (https://www.fenicsproject.org)
#
# SPDX-License-Identifier:    LGPL-3.0-or-later
#
# Modified by Anders Logg, 2008-2009
# Modified by Massimiliano Leoni, 2016.

import ufl
from ufl.checks import is_python_scalar, is_scalar_constant_expression
from ufl.core.expr import Expr
from ufl.protocols import id_or_none

# Export list for ufl.classes
__all_classes__ = ["Integral"]


[docs]class Integral(object): """An integral over a single domain.""" __slots__ = ( "_integrand", "_integral_type", "_ufl_domain", "_subdomain_id", "_metadata", "_subdomain_data", ) def __init__(self, integrand, integral_type, domain, subdomain_id, metadata, subdomain_data): """Initialise.""" if not isinstance(integrand, Expr): raise ValueError("Expecting integrand to be an Expr instance.") self._integrand = integrand self._integral_type = integral_type self._ufl_domain = domain self._subdomain_id = subdomain_id self._metadata = metadata self._subdomain_data = subdomain_data
[docs] def reconstruct( self, integrand=None, integral_type=None, domain=None, subdomain_id=None, metadata=None, subdomain_data=None, ): """Construct a new Integral object with some properties replaced with new values. Example: <a = Integral instance> b = a.reconstruct(expand_compounds(a.integrand())) c = a.reconstruct(metadata={'quadrature_degree':2}) """ if integrand is None: integrand = self.integrand() if integral_type is None: integral_type = self.integral_type() if domain is None: domain = self.ufl_domain() if subdomain_id is None: subdomain_id = self.subdomain_id() if metadata is None: metadata = self.metadata() if subdomain_data is None: subdomain_data = self._subdomain_data return Integral(integrand, integral_type, domain, subdomain_id, metadata, subdomain_data)
[docs] def integrand(self): """Return the integrand expression, which is an ``Expr`` instance.""" return self._integrand
[docs] def integral_type(self): """Return the domain type of this integral.""" return self._integral_type
[docs] def ufl_domain(self): """Return the integration domain of this integral.""" return self._ufl_domain
[docs] def subdomain_id(self): """Return the subdomain id of this integral.""" return self._subdomain_id
[docs] def metadata(self): """Return the compiler metadata this integral has been annotated with.""" return self._metadata
[docs] def subdomain_data(self): """Return the domain data of this integral.""" return self._subdomain_data
def __neg__(self): """Negate.""" return self.reconstruct(-self._integrand) def __mul__(self, scalar): """Multiply.""" if not is_python_scalar(scalar): raise ValueError("Cannot multiply an integral with non-constant values.") return self.reconstruct(scalar * self._integrand) def __rmul__(self, scalar): """Multiply.""" if not is_scalar_constant_expression(scalar): raise ValueError( "An integral can only be multiplied by a globally constant scalar expression." ) return self.reconstruct(scalar * self._integrand) def __str__(self): """Format as a string.""" fmt = "{ %s } * %s(%s[%s], %s)" mname = ufl.measure.integral_type_to_measure_name[self._integral_type] s = fmt % (self._integrand, mname, self._ufl_domain, self._subdomain_id, self._metadata) return s def __repr__(self): """Representation.""" return ( f"Integral({self._integrand!r}, {self._integral_type!r}, {self._ufl_domain!r}, " f"{self._subdomain_id!r}, {self._metadata!r}, {self._subdomain_data!r})" ) def __eq__(self, other): """Check equality.""" return ( isinstance(other, Integral) and self._integral_type == other._integral_type and self._ufl_domain == other._ufl_domain and self._subdomain_id == other._subdomain_id and self._integrand == other._integrand and self._metadata == other._metadata and id_or_none(self._subdomain_data) == id_or_none(other._subdomain_data) ) def __hash__(self): """Hash.""" # Assuming few collisions by ignoring hash(self._metadata) (a # dict is not hashable but we assume it is immutable in # practice) hashdata = ( hash(self._integrand), self._integral_type, hash(self._ufl_domain), self._subdomain_id, id_or_none(self._subdomain_data), ) return hash(hashdata)