Commit b4ccb638 authored by Tjerk Vreeken's avatar Tjerk Vreeken Committed by Teresa Piovesan

SimulationProblem: Fix scaling of equations with nominals

SimulationProblem was only ever using the nominals defined in the Modelica
file, even if e.g. the user was overriding get_variable_nominal().

Also note that variable nominals can be symbolic, but that we would like
to handle numeric values/floats as much as possible. We therefore
evaluate the nominals to their numeric values as soon as we know all
parameter values.
parent 5d8228d9
......@@ -236,12 +236,30 @@ class SimulationProblem:
logger.debug('SimulationProblem: Setting parameter {} = {}'.format(, val))
self.set_var(, val)
# Nominals can be symbolic, written in terms of parameters. After all
# parameter values are known, we evaluate the numeric values of the
# nominals.
nominal_vars = list(itertools.chain(
self.__pymoca_model.states, self.__pymoca_model.alg_states, self.__pymoca_model.der_states))
symbolic_nominals = ca.vertcat(*[self.get_variable_nominal( for v in nominal_vars])
nominal_evaluator = ca.Function('nominal_evaluator', self.__mx['parameters'], [symbolic_nominals])
n_parameters = len(self.__mx['parameters'])
if n_parameters > 0:
[evaluated_nominals] =[-n_parameters:])
[evaluated_nominals] =[])
evaluated_nominals = np.array(evaluated_nominals).ravel()
nominal_dict = { n for v, n in zip(nominal_vars, evaluated_nominals)}
# Assemble initial residuals and set values from start attributes into the state vector
constrained_residuals = []
minimized_residuals = []
for var in itertools.chain(self.__pymoca_model.states, self.__pymoca_model.alg_states):
var_name =
var_nominal = self.get_variable_nominal(var_name)
var_nominal = nominal_dict[var_name]
# Attempt to cast var.start to python type
mx_start = ca.MX(var.start)
......@@ -310,7 +328,11 @@ class SimulationProblem:
# Make a list of unscaled symbols and a list of their scaled equivalent
unscaled_symbols = []
scaled_symbols = []
for sym_name, nominal in self.__nominals.items():
for sym_name, nominal in nominal_dict.items():
if nominal == 1.0:
# Nothing to scale
# Add the symbol to the lists
symbol = self.__sym_dict[sym_name]
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment