/usr/lib/python2.7/dist-packages/ufl/variable.py is in python-ufl 1.3.0-1.
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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 | """Defines the Variable and Label classes, used to label
expressions as variables for differentiation."""
# Copyright (C) 2008-2013 Martin Sandve Alnes
#
# This file is part of UFL.
#
# UFL 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.
#
# UFL 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 UFL. If not, see <http://www.gnu.org/licenses/>.
#
# First added: 2008-05-20
# Last changed: 2011-06-02
from ufl.common import counted_init
from ufl.log import error
from ufl.assertions import ufl_assert
from ufl.expr import Expr
from ufl.terminal import UtilityType
from ufl.operatorbase import WrapperType
from ufl.constantvalue import as_ufl
class Label(UtilityType):
__slots__ = ("_count",)
_globalcount = 0
def __init__(self, count=None):
UtilityType.__init__(self)
counted_init(self, count, Label)
def count(self):
return self._count
def __str__(self):
return "Label(%d)" % self._count
def __repr__(self):
return "Label(%d)" % self._count
class Variable(WrapperType):
"""A Variable is a representative for another expression.
It will be used by the end-user mainly for defining
a quantity to differentiate w.r.t. using diff.
Example::
e = <...>
e = variable(e)
f = exp(e**2)
df = diff(f, e)
"""
__slots__ = ("_expression", "_label",)
def __init__(self, expression, label=None):
WrapperType.__init__(self)
expression = as_ufl(expression)
ufl_assert(isinstance(expression, Expr), "Expecting Expr.")
self._expression = expression
if label is None:
label = Label()
ufl_assert(isinstance(label, Label), "Expecting a Label.")
self._label = label
def operands(self):
return (self._expression, self._label)
def free_indices(self):
return self._expression.free_indices()
def index_dimensions(self):
return self._expression.index_dimensions()
def shape(self):
return self._expression.shape()
def cell(self):
return self._expression.cell()
def domain(self):
return self._expression.domain()
def is_cellwise_constant(self):
return self._expression.is_cellwise_constant()
def evaluate(self, x, mapping, component, index_values):
a = self._expression.evaluate(x, mapping, component, index_values)
return a
def expression(self):
return self._expression
def label(self):
return self._label
def __eq__(self, other):
return isinstance(other, Variable) and self._label == other._label and self._expression == other._expression
def __str__(self):
return "var%d(%s)" % (self._label.count(), self._expression)
def __repr__(self):
return "Variable(%r, %r)" % (self._expression, self._label)
def __getnewargs__(self):
return ()
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