/usr/lib/python2.7/dist-packages/ufl/indexsum.py is in python-ufl 1.4.0-1.
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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 | """This module defines the IndexSum class."""
# Copyright (C) 2008-2014 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/>.
from ufl.log import error
from ufl.assertions import ufl_assert
from ufl.expr import Expr
from ufl.operatorbase import AlgebraOperator
from ufl.indexing import Index, MultiIndex, as_multi_index
from ufl.precedence import parstr
from ufl.common import EmptyDict
#--- Sum over an index ---
class IndexSum(AlgebraOperator):
__slots__ = ("_summand", "_index", "_dimension", "_free_indices", "_index_dimensions")
def __new__(cls, summand, index):
if not isinstance(summand, Expr):
error("Expecting Expr instance, not %s." % repr(summand))
from ufl.constantvalue import Zero
if isinstance(summand, Zero):
sh = summand.shape()
if isinstance(index, Index):
j = index
elif isinstance(index, MultiIndex):
if len(index) != 1:
error("Expecting a single Index only.")
j, = index
fi = tuple(i for i in summand.free_indices() if not i == j)
idims = dict(summand.index_dimensions())
del idims[j]
return Zero(sh, fi, idims)
return AlgebraOperator.__new__(cls)
def __init__(self, summand, index):
AlgebraOperator.__init__(self)
if isinstance(index, Index):
j = index
elif isinstance(index, MultiIndex):
if len(index) != 1:
error("Expecting a single Index only.")
j, = index
self._summand = summand
self._index_dimensions = dict(summand.index_dimensions())
self._free_indices = tuple(i for i in summand.free_indices() if not i == j)
d = self._index_dimensions[j]
self._index = as_multi_index(index, (d,))
ufl_assert(isinstance(self._index, MultiIndex), "Error in initialization of index sum.")
self._dimension = d
del self._index_dimensions[j]
if not self._index_dimensions:
self._index_dimensions = EmptyDict
def index(self):
return self._index[0]
def dimension(self):
return self._dimension
def operands(self):
return (self._summand, self._index)
def free_indices(self):
return self._free_indices
def index_dimensions(self):
return self._index_dimensions
def shape(self):
return self._summand.shape()
def is_cellwise_constant(self):
"Return whether this expression is spatially constant over each cell."
return self._summand.is_cellwise_constant()
def evaluate(self, x, mapping, component, index_values):
i, = self._index
tmp = 0
for k in range(self._dimension):
index_values.push(i, k)
tmp += self._summand.evaluate(x, mapping, component, index_values)
index_values.pop()
return tmp
def __str__(self):
return "sum_{%s} %s " % (str(self._index), parstr(self._summand, self))
def __repr__(self):
return "IndexSum(%r, %r)" % (self._summand, self._index)
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