import os.path
import dolfin
from domain import Domain
[docs]class RectangularDomain(Domain):
""" Create a rectangular domain.
:param x0: The x coordinate of the bottom-left.
:type x0: float
:param y0: The y coordinate of the bottom-left.
:type y0: float
:param x1: The x coordinate of the top-right corner.
:type x1: float
:param y1: The y coordinate of the top-right corner.
:type y1: float
"""
def __init__(self, x0, y0, x1, y1, nx, ny):
#: A :class:`dolfin.Mesh` containing the mesh.
self.mesh = dolfin.RectangleMesh(x0, x0, x1, y1, nx, ny)
class Left(dolfin.SubDomain):
def inside(self, x, on_boundary):
return on_boundary and dolfin.near(x[0], x0)
class Right(dolfin.SubDomain):
def inside(self, x, on_boundary):
return on_boundary and dolfin.near(x[0], x1)
class Sides(dolfin.SubDomain):
def inside(self, x, on_boundary):
return on_boundary and (dolfin.near(x[1], y0) or dolfin.near(x[1], y1))
# Initialize sub-domain instances
left = Left()
right = Right()
sides = Sides()
# Create facet markers
#: A :class:`dolfin.FacetFunction` containing the surface markers.
self.facet_ids = dolfin.FacetFunction('size_t', self.mesh)
self.facet_ids.set_all(0)
left.mark(self.facet_ids, 1)
right.mark(self.facet_ids, 2)
sides.mark(self.facet_ids, 3)
#: A :class:`dolfin.Measure` for the facet parts.
self._ds = dolfin.Measure('ds')[self.facet_ids]
#: A :class:`dolfin.CellFunction` containing the area markers.
self.cell_ids = dolfin.CellFunction("size_t", self.mesh)
self.cell_ids.set_all(0)
#: A :class:`dolfin.Measure` for the cell cell_ids.
self._dx = dolfin.Measure("dx")[self.cell_ids]