def _make_identity(self, sh):
"Create a higher order identity tensor to represent dv/dv."
res = None
if sh == ():
# Scalar dv/dv is scalar
return FloatValue(1.0)
elif len(sh) == 1:
# Vector v makes dv/dv the identity matrix
return Identity(sh[0])
else:
# TODO: Add a type for this higher order identity?
# II[i0,i1,i2,j0,j1,j2] = 1 if all((i0==j0, i1==j1, i2==j2)) else 0
# Tensor v makes dv/dv some kind of higher rank identity tensor
ind1 = ()
ind2 = ()
for d in sh:
i, j = indices(2)
dij = Identity(d)[i, j]
if res is None:
res = dij
else:
res *= dij
ind1 += (i, )
ind2 += (j, )
fp = as_tensor(res, ind1 + ind2)
return fp
def __init__(self, topological_dimension):
GenericDerivativeRuleset.__init__(self,
var_shape=(topological_dimension, ))
self._Id = Identity(topological_dimension)
def __init__(self, geometric_dimension):
GenericDerivativeRuleset.__init__(self,
var_shape=(geometric_dimension, ))
self._Id = Identity(geometric_dimension)