/usr/lib/python2.7/dist-packages/dolfin/functions/specialfunctions.py is in python-dolfin 1.3.0+dfsg-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 | # -*- coding: utf-8 -*-
"""This module defines some special functions
(originally defined in SpecialFunctions.h)."""
# Copyright (C) 2008-2011 Anders Logg
#
# This file is part of DOLFIN.
#
# DOLFIN is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# DOLFIN is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with DOLFIN. If not, see <http://www.gnu.org/licenses/>.
#
# Modified by Johan Hake 2008-2009
# Modified by Garth N. Wells 2010
#
# First added: 2008-12-08
# Last changed: 2011-11-15
__all__ = ["MeshCoordinates", "FacetArea", "FacetNormal", "CellSize", "CellVolume"]
# Import UFL and SWIG-generated extension module (DOLFIN C++)
import ufl
import dolfin.cpp as cpp
# Local imports
from dolfin.functions.expression import Expression
class MeshCoordinates(Expression, ufl.Coefficient, cpp.MeshCoordinates):
def __init__(self, mesh):
"Create function that evaluates to the mesh coordinates at each vertex."
domain = mesh.ufl_cell()
self._ufl_element = ufl.VectorElement("Lagrange", domain, 1)
ufl.Coefficient.__init__(self, self._ufl_element)
cpp.MeshCoordinates.__init__(self, mesh)
MeshCoordinates.__doc__ = cpp.MeshCoordinates.__doc__
class FacetArea(Expression, ufl.Coefficient, cpp.FacetArea):
def __init__(self, mesh):
"""
Create function that evaluates to the facet area/length on each facet.
*Arguments*
mesh
a :py:class:`Mesh <dolfin.cpp.Mesh>`.
*Example of usage*
.. code-block:: python
mesh = UnitSquare(4,4)
fa = FacetArea(mesh)
"""
domain = mesh.ufl_cell()
self._ufl_element = ufl.FiniteElement("Discontinuous Lagrange", domain, 0)
ufl.Coefficient.__init__(self, self._ufl_element)
cpp.FacetArea.__init__(self, mesh)
FacetArea.__doc__ = cpp.FacetArea.__doc__
# Simple definition of FacetNormal via UFL
def FacetNormal(mesh):
"""
Return facet normal function for given mesh.
*Arguments*
mesh
a :py:class:`Mesh <dolfin.cpp.Mesh>`.
*Example of usage*
.. code-block:: python
mesh = UnitSquare(4,4)
n = FacetNormal(mesh)
"""
cell = mesh.ufl_cell()
return cell.n
# Simple definition of CellSize via UFL
def CellSize(mesh):
"""
Return cell size function for given mesh.
*Arguments*
mesh
a :py:class:`Mesh <dolfin.cpp.Mesh>`.
*Example of usage*
.. code-block:: python
mesh = UnitSquare(4,4)
h = CellSize(mesh)
"""
cell = mesh.ufl_cell()
return 2.0*cell.circumradius
# Simple definition of CellVolume via UFL
def CellVolume(mesh):
"""
Return cell volume function for given mesh.
*Arguments*
mesh
a :py:class:`Mesh <dolfin.cpp.Mesh>`.
*Example of usage*
.. code-block:: python
mesh = UnitSquare(4,4)
vol = CellVolume(mesh)
"""
cell = mesh.ufl_cell()
return cell.volume
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