def purge_list_tensors(expr):
"""Get rid of all ListTensor instances by expanding
expressions to use their components directly.
Will usually increase the size of the expression."""
if any(isinstance(subexpr, ListTensor) for subexpr in unique_pre_traversal(expr)):
return expand_indices(expr) # TODO: Only expand what's necessary to get rid of list tensors
return expr
def purge_list_tensors(expr):
"""Get rid of all ListTensor instances by expanding
expressions to use their components directly.
Will usually increase the size of the expression."""
if any(
isinstance(subexpr, ListTensor)
for subexpr in unique_pre_traversal(expr)):
return expand_indices(
expr
) # TODO: Only expand what's necessary to get rid of list tensors
return expr
def extract_type(a, ufl_type):
"""Build a set of all objects of class ufl_type found in a.
The argument a can be a Form, Integral or Expr."""
if issubclass(ufl_type, Terminal):
# Optimization
return set(o for e in iter_expressions(a)
for o in traverse_unique_terminals(e)
if isinstance(o, ufl_type))
else:
return set(o for e in iter_expressions(a)
for o in unique_pre_traversal(e) if isinstance(o, ufl_type))
def test_pre_and_post_traversal():
element = FiniteElement("CG", "triangle", 1)
v = TestFunction(element)
f = Coefficient(element)
g = Coefficient(element)
p1 = f * v
p2 = g * v
s = p1 + p2
# NB! These traversal algorithms are intended to guarantee only
# parent before child and vice versa, not this particular
# ordering:
assert list(pre_traversal(s)) == [s, p2, g, v, p1, f, v]
assert list(post_traversal(s)) == [g, v, p2, f, v, p1, s]
assert list(unique_pre_traversal(s)) == [s, p2, g, v, p1, f]
assert list(unique_post_traversal(s)) == [v, f, p1, g, p2, s]
def test_pre_and_post_traversal():
element = FiniteElement("CG", "triangle", 1)
v = TestFunction(element)
f = Coefficient(element)
g = Coefficient(element)
p1 = f * v
p2 = g * v
s = p1 + p2
# NB! These traversal algorithms are intended to guarantee only
# parent before child and vice versa, not this particular
# ordering:
assert list(pre_traversal(s)) == [s, p2, g, v, p1, f, v]
assert list(post_traversal(s)) == [g, v, p2, f, v, p1, s]
assert list(unique_pre_traversal(s)) == [s, p2, g, v, p1, f]
assert list(unique_post_traversal(s)) == [v, f, p1, g, p2, s]
def build_graph(expr): # O(n)
"""Build a linearized graph from an UFL Expr.
Returns G = (V, E), with V being a list of
graph nodes (Expr objects) in post traversal
ordering and E being a list of edges. Each edge
is represented as a (i, j) tuple where i and j
are vertex indices into V.
"""
V = []
E = []
handled = {}
for v in reversed(list(unique_pre_traversal(expr))):
i = handled.get(v)
if i is None:
i = len(V)
handled[v] = i
V.append(v)
for o in v.ufl_operands:
j = handled[o]
e = (i, j)
E.append(e)
G = V, E
return G
def build_graph(expr): # O(n)
"""Build a linearized graph from an UFL Expr.
Returns G = (V, E), with V being a list of
graph nodes (Expr objects) in post traversal
ordering and E being a list of edges. Each edge
is represented as a (i, j) tuple where i and j
are vertex indices into V.
"""
V = []
E = []
handled = {}
for v in reversed(list(unique_pre_traversal(expr))):
i = handled.get(v)
if i is None:
i = len(V)
handled[v] = i
V.append(v)
for o in v.ufl_operands:
j = handled[o]
e = (i, j)
E.append(e)
G = V, E
return G
def __unused__extract_classes(a):
"""Build a set of all unique Expr subclasses used in a.
The argument a can be a Form, Integral or Expr."""
return set(o._ufl_class_ for e in iter_expressions(a)
for o in unique_pre_traversal(e))
