def callback():
# Derivatives must be evaluated before the introduction of indirect accesses
try:
_expr = expr.evaluate
except AttributeError:
# E.g., a generic SymPy expression or a number
_expr = expr
variables = list(retrieve_function_carriers(_expr))
# Need to get origin of the field in case it is staggered
# TODO: handle each variable staggereing spearately
field_offset = variables[0].origin
# List of indirection indices for all adjacent grid points
idx_subs, temps = self._interpolation_indices(variables, offset,
field_offset=field_offset)
# Substitute coordinate base symbols into the interpolation coefficients
args = [_expr.xreplace(v_sub) * b.xreplace(v_sub)
for b, v_sub in zip(self._interpolation_coeffs, idx_subs)]
# Accumulate point-wise contributions into a temporary
rhs = Symbol(name='sum', dtype=self.sfunction.dtype)
summands = [Eq(rhs, 0., implicit_dims=self.sfunction.dimensions)]
summands.extend([Inc(rhs, i, implicit_dims=self.sfunction.dimensions)
for i in args])
# Write/Incr `self`
lhs = self.sfunction.subs(self_subs)
last = [Inc(lhs, rhs)] if increment else [Eq(lhs, rhs)]
return temps + summands + last
def callback():
# Derivatives must be evaluated before the introduction of indirect accesses
try:
_expr = expr.evaluate
except AttributeError:
# E.g., a generic SymPy expression or a number
_expr = expr
variables = list(retrieve_function_carriers(_expr)) + [field]
# Need to get origin of the field in case it is staggered
field_offset = field.origin
# List of indirection indices for all adjacent grid points
idx_subs, temps = self._interpolation_indices(
variables, offset, field_offset=field_offset)
# Substitute coordinate base symbols into the interpolation coefficients
eqns = [
Inc(field.xreplace(vsub),
_expr.xreplace(vsub) * b,
implicit_dims=self.sfunction.dimensions)
for b, vsub in zip(self._interpolation_coeffs, idx_subs)
]
return temps + eqns