# Copyright (C) 2014 Marie E. Rognes (meg@simula.no)
# Use and modify at will
# Last changed: 2016-10-19
__all__ = ["Markerwise", "handle_markerwise", "rhs_with_markerwise_field"]
from dolfinimport import dx, Measure, error
[docs]def handle_markerwise(g, classtype):
# Handle stimulus
if (g is None \
or isinstance(g, classtype) \
or isinstance(g, Markerwise) \
or isinstance(g, object)): ## HAHAHA
return g
else:
msg = "Expecting stimulus to be a %s or Markerwise, not %r " \
% (str(classtype), g)
error(msg)
[docs]def rhs_with_markerwise_field(g, mesh, v):
if g is None:
dz = dx
rhs = 0.0
elif isinstance(g, Markerwise):
markers = g.markers()
dz = Measure("dx", domain=mesh, subdomain_data=markers)
rhs = sum([g*v*dz(i) for (i, g) in zip(g.keys(), g.values())])
else:
dz = dx
rhs = g*v*dz()
return (dz, rhs)
[docs]class Markerwise(object):
"""A container class representing an object defined by a number of
objects combined with a mesh function defining mesh domains and a
map between the these.
*Arguments*
objects (tuple)
the different objects
keys (tuple of ints)
a map from the objects to the domains marked in markers
markers (:py:class:`dolfin.MeshFunction`)
a mesh function mapping which domains the mesh consist of
*Example of usage*
Given (g0, g1), (2, 5) and markers, let
g = g0 on domains marked by 2 in markers
g = g1 on domains marked by 5 in markers
letting::
g = Markerwise((g0, g1), (2, 5), markers)
"""
def __init__(self, objects, keys, markers):
"Create Markerwise from given input."
# Check input
assert len(objects) == len(keys), \
"Expecting the number of objects to equal the number of keys"
# Store attributes:
self._objects = dict(zip(keys, objects))
self._markers = markers
[docs] def values(self):
"The objects"
return self._objects.values()
[docs] def keys(self):
"The keys or domain numbers"
return self._objects.keys()
[docs] def markers(self):
"The markers"
return self._markers
def __getitem__(self, key):
"The objects"
return self._objects[key]
if __name__ == "__main__":
from dolfin import *
g1 = Expression("1.0", degree=1)
g5 = Expression("sin(pi*x[0])", degree=3)
mesh = UnitSquareMesh(16, 16)
class SampleDomain(SubDomain):
def inside(self, x, on_boundary):
return all(x <= 0.5 + DOLFIN_EPS)
markers = MeshFunction("size_t", mesh, mesh.topology().dim(), 1)
domain = SampleDomain()
domain.mark(markers, 5)
g = Markerwise((g1, g5), (1, 5), markers)
plot(g.markers())
for v in g.values():
plot(v, mesh=mesh)
interactive()