def parameters(self):
"""
Return a dictionary of parameter values extracted from the Modelica model
"""
# Create AliasDict
parameters = AliasDict(self.alias_relation)
# Update with model parameters
parameters.update(
{p.symbol.name(): p.value
for p in self.__pymoca_model.parameters})
return parameters
def initialize(self, config_file=None):
# Set up experiment
self.setup_experiment(0, self.__timeseries_import_times[-1], self.__dt)
# Load parameters from parameter config
self.__parameter_variables = set(self.get_parameter_variables())
logger.debug("Model parameters are {}".format(
self.__parameter_variables))
for parameter, value in self.__parameters.items():
if parameter in self.__parameter_variables:
logger.debug("PIMixin: Setting parameter {} = {}".format(
parameter, value))
self.set_var(parameter, value)
# Load input variable names
self.__input_variables = set(self.get_input_variables().keys())
# Set input values
for variable in self.__input_variables:
value = self.__timeseries_import_dict[variable][
self.__timeseries_import.forecast_index]
if np.isfinite(value):
self.set_var(variable, value)
else:
logger.debug(
'PIMixin: Found bad value {} at index [{}] in timeseries aliased to input {}'
.format(value, self.__timeseries_import.forecast_index,
variable))
logger.debug("Model inputs are {}".format(self.__input_variables))
# Empty output
self.__output_variables = self.get_output_variables()
n_times = len(self.__timeseries_import_times)
self.__output = AliasDict(self.alias_relation)
self.__output.update({
variable: np.full(n_times, np.nan)
for variable in self.__output_variables
})
# Call super, which will also initialize the model itself
super().initialize(config_file)
# Extract consistent t0 values
for variable in self.__output_variables:
self.__output[variable][self.__timeseries_import.
forecast_index] = self.get_var(variable)
def initial_state(self, ensemble_member):
history = self.history(ensemble_member)
return AliasDict(
self.alias_relation, {
variable: timeseries.values[-1]
for variable, timeseries in history.items()
})
def seed(self, ensemble_member: int) -> AliasDict:
"""
Seeding data. The optimization algorithm is seeded with the data returned by this method.
:param ensemble_member: The ensemble member index.
:returns: A dictionary of variable names and seed time series.
"""
return AliasDict(self.alias_relation)
def lookup_tables(self, ensemble_member: int) -> AliasDict:
"""
Returns a dictionary of lookup tables.
:param ensemble_member: The ensemble member index.
:returns: A dictionary of variable names and lookup tables.
"""
return AliasDict(self.alias_relation)
def constant_inputs(self, ensemble_member: int) -> AliasDict:
"""
Returns a dictionary of constant inputs.
:param ensemble_member: The ensemble member index.
:returns: A dictionary of constant input names and time series.
"""
return AliasDict(self.alias_relation)
def parameters(self, ensemble_member: int) -> AliasDict:
"""
Returns a dictionary of parameters.
:param ensemble_member: The ensemble member index.
:returns: A dictionary of parameter names and values.
"""
return AliasDict(self.alias_relation)
def initial_state(self, ensemble_member):
initial_state = AliasDict(self.alias_relation)
# Initial conditions obtained from start attributes.
for v in self.__pymoca_model.states:
if v.fixed:
initial_state[v.symbol.name()] = v.start
return initial_state
def __nominals(self):
# Make the dict
nominal_dict = AliasDict(self.alias_relation)
# Grab parameters and their values
parameters = self.parameters(0)
parameter_values = [
parameters.get(param.name(), param)
for param in self.__mx['parameters']
]
# Iterate over nominalizable states
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
sym_name = v.symbol.name()
# For type consistency, cast to MX
nominal = ca.MX(v.nominal)
# If nominal contains parameter symbols, substitute them
if not nominal.is_constant():
[nominal] = substitute_in_external([nominal],
self.__mx['parameters'],
parameter_values)
if nominal.is_constant():
# Take absolute value (nominal sign is meaningless- a nominal is a magnitude)
nominal = ca.fabs(nominal)
# If nominal is 0 or 1, we just use the default (1.0)
if nominal.is_zero() or (nominal - 1).is_zero():
continue
# Cast to numpy array
nominal = nominal.to_DM().full().flatten()
try:
# Attempt to cast to python scalar before storing
nominal_dict[sym_name] = nominal.item()
except ValueError:
# Nominal is numpy array- store it as such
nominal_dict[sym_name] = nominal
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug(
"ModelicaMixin: Set nominal value for variable {} to {}"
.format(sym_name, nominal_dict[sym_name]))
else:
logger.warning(
"ModelicaMixin: Could not set nominal value for {}".format(
sym_name))
return nominal_dict
def history(self, ensemble_member: int) -> AliasDict:
"""
Returns the state history. Uses the initial_state() method by default.
:param ensemble_member: The ensemble member index.
:returns: A dictionary of variable names and historical time series (up to and including t0).
"""
initial_state = self.initial_state(ensemble_member)
return AliasDict(
self.alias_relation, {
variable: Timeseries(np.array([self.initial_time]),
np.array([state]))
for variable, state in initial_state.items()
})
def bounds(self) -> AliasDict:
"""
Returns variable bounds as a dictionary mapping variable names to a pair of bounds.
A bound may be a constant, or a time series.
:returns: A dictionary of variable names and ``(upper, lower)`` bound pairs.
The bounds may be numbers or :class:`Timeseries` objects.
Example::
def bounds(self):
return {'x': (1.0, 2.0), 'y': (2.0, 3.0)}
"""
return AliasDict(self.alias_relation)
def initial_state(self, ensemble_member: int) -> AliasDict:
"""
The initial state.
The default implementation uses t0 data returned by the ``history`` method.
:param ensemble_member: The ensemble member index.
:returns: A dictionary of variable names and initial state (t0) values.
"""
t0 = self.initial_time
history = self.history(ensemble_member)
return AliasDict(
self.alias_relation, {
variable: self.interpolate(t0, timeseries.times,
timeseries.values)
for variable, timeseries in history.items()
})
def history(self, ensemble_member):
# Load history
history = AliasDict(self.alias_relation)
end_index = self.__timeseries_import.forecast_index + 1
variable_list = self.dae_variables['states'] + self.dae_variables['algebraics'] + \
self.dae_variables['control_inputs'] + self.dae_variables['constant_inputs']
for variable in variable_list:
variable = variable.name()
try:
history[variable] = Timeseries(
self.__timeseries_import_times[:end_index],
self.__timeseries_import_dict[ensemble_member][variable]
[:end_index])
except KeyError:
pass
else:
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("Read history for state {}".format(variable))
return history
def initial_state(self) -> AliasDict:
"""
The initial state.
:returns: A dictionary of variable names and initial state (t0) values.
"""
t0 = self.get_start_time()
initial_state_dict = AliasDict(self.alias_relation)
for variable in list(self.get_state_variables()) + list(
self.get_input_variables()):
try:
initial_state_dict[variable] = self.timeseries_at(variable, t0)
except KeyError:
pass
except NotImplementedError:
pass
else:
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("Read intial state for {}".format(variable))
return initial_state_dict
def get_state_variables(self):
return AliasDict(
self.alias_relation, {
sym.name(): sym
for sym in (self.__mx['states'] + self.__mx['algebraics'])
})
def __init__(self, **kwargs):
# Check arguments
assert ('model_folder' in kwargs)
# Log pymoca version
logger.debug("Using pymoca {}.".format(pymoca.__version__))
# Transfer model from the Modelica .mo file to CasADi using pymoca
if 'model_name' in kwargs:
model_name = kwargs['model_name']
else:
if hasattr(self, 'model_name'):
model_name = self.model_name
else:
model_name = self.__class__.__name__
self.__pymoca_model = pymoca.backends.casadi.api.transfer_model(
kwargs['model_folder'], model_name, self.compiler_options())
# Extract the CasADi MX variables used in the model
self.__mx = {}
self.__mx['time'] = [self.__pymoca_model.time]
self.__mx['states'] = [v.symbol for v in self.__pymoca_model.states]
self.__mx['derivatives'] = [
v.symbol for v in self.__pymoca_model.der_states
]
self.__mx['algebraics'] = [
v.symbol for v in self.__pymoca_model.alg_states
]
self.__mx['parameters'] = [
v.symbol for v in self.__pymoca_model.parameters
]
self.__mx['control_inputs'] = []
self.__mx['constant_inputs'] = []
self.__mx['lookup_tables'] = []
# Merge with user-specified delayed feedback
delayed_feedback_variables = list(
map(lambda delayed_feedback: delayed_feedback[1],
self.delayed_feedback()))
for v in self.__pymoca_model.inputs:
if v.symbol.name() in delayed_feedback_variables:
# Delayed feedback variables are local to each ensemble, and
# therefore belong to the collection of algebraic variables,
# rather than to the control inputs.
self.__mx['algebraics'].append(v.symbol)
else:
if v.symbol.name() in kwargs.get('lookup_tables', []):
self.__mx['lookup_tables'].append(v.symbol)
elif v.fixed:
self.__mx['constant_inputs'].append(v.symbol)
else:
self.__mx['control_inputs'].append(v.symbol)
# Initialize nominals and types
# These are not in @cached dictionary properties for backwards compatibility.
self.__python_types = AliasDict(self.alias_relation)
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
self.__python_types[v.symbol.name()] = v.python_type
# Initialize dae and initial residuals
# These are not in @cached dictionary properties so that we need to create the list
# of function arguments only once.
variable_lists = [
'states', 'der_states', 'alg_states', 'inputs', 'constants',
'parameters'
]
function_arguments = [self.__pymoca_model.time] + [
ca.veccat(*[
v.symbol for v in getattr(self.__pymoca_model, variable_list)
]) for variable_list in variable_lists
]
self.__dae_residual = self.__pymoca_model.dae_residual_function(
*function_arguments)
if self.__dae_residual is None:
self.__dae_residual = ca.MX()
self.__initial_residual = self.__pymoca_model.initial_residual_function(
*function_arguments)
if self.__initial_residual is None:
self.__initial_residual = ca.MX()
# Log variables in debug mode
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("ModelicaMixin: Found states {}".format(', '.join(
[var.name() for var in self.__mx['states']])))
logger.debug("ModelicaMixin: Found derivatives {}".format(
', '.join([var.name() for var in self.__mx['derivatives']])))
logger.debug("ModelicaMixin: Found algebraics {}".format(', '.join(
[var.name() for var in self.__mx['algebraics']])))
logger.debug("ModelicaMixin: Found control inputs {}".format(
', '.join([var.name()
for var in self.__mx['control_inputs']])))
logger.debug("ModelicaMixin: Found constant inputs {}".format(
', '.join([var.name()
for var in self.__mx['constant_inputs']])))
logger.debug("ModelicaMixin: Found parameters {}".format(', '.join(
[var.name() for var in self.__mx['parameters']])))
# Call parent class first for default behaviour.
super().__init__(**kwargs)
def pre(self):
# Call parent class first for default behaviour.
super().pre()
# rtcParameterConfig
self.__parameter_config = []
try:
for pi_parameter_config_basename in self.pi_parameter_config_basenames:
self.__parameter_config.append(
pi.ParameterConfig(self.__input_folder,
pi_parameter_config_basename))
except IOError:
raise Exception("PIMixin: {}.xml not found in {}.".format(
pi_parameter_config_basename, self.__input_folder))
try:
self.__parameter_config_numerical = pi.ParameterConfig(
self.__input_folder,
self.pi_parameter_config_numerical_basename)
except IOError:
self.__parameter_config_numerical = None
try:
self.__timeseries_import = pi.Timeseries(
self.__data_config,
self.__input_folder,
self.timeseries_import_basename,
binary=self.pi_binary_timeseries,
pi_validate_times=self.pi_validate_timeseries)
except IOError:
raise Exception("PIMixin: {}.xml not found in {}.".format(
self.timeseries_import_basename, self.__input_folder))
self.__timeseries_export = pi.Timeseries(
self.__data_config,
self.__output_folder,
self.timeseries_export_basename,
binary=self.pi_binary_timeseries,
pi_validate_times=False,
make_new_file=True)
# Convert timeseries timestamps to seconds since t0 for internal use
self.__timeseries_import_times = self.__datetime_to_sec(
self.__timeseries_import.times)
# Timestamp check
if self.pi_validate_timeseries:
for i in range(len(self.__timeseries_import_times) - 1):
if self.__timeseries_import_times[
i] >= self.__timeseries_import_times[i + 1]:
raise Exception(
'PIMixin: Time stamps must be strictly increasing.')
if self.equidistant:
# Check if the timeseries are truly equidistant
if self.pi_validate_timeseries:
dt = self.__timeseries_import_times[
1] - self.__timeseries_import_times[0]
for i in range(len(self.__timeseries_import_times) - 1):
if self.__timeseries_import_times[
i + 1] - self.__timeseries_import_times[i] != dt:
raise Exception(
'PIMixin: Expecting equidistant timeseries, the time step '
'towards {} is not the same as the time step(s) before. Set '
'unit to nonequidistant if this is intended.'.
format(self.__timeseries_import.times[i + 1]))
# Stick timeseries into an AliasDict
self.__timeseries_import_dict = [
AliasDict(self.alias_relation)
for ensemble_member in range(self.ensemble_size)
]
for ensemble_member in range(self.ensemble_size):
for key, value in self.__timeseries_import.items(ensemble_member):
self.__timeseries_import_dict[ensemble_member][key] = value
class ModelicaMixin(OptimizationProblem):
"""
Adds a `Modelica <http://www.modelica.org/>`_ model to your optimization problem.
During preprocessing, the Modelica files located inside the ``model`` subfolder are loaded.
:cvar modelica_library_folders:
Folders in which any referenced Modelica libraries are to be found. Default is an empty list.
"""
# Folders in which the referenced Modelica libraries are found
modelica_library_folders = []
def __init__(self, **kwargs):
# Check arguments
assert ('model_folder' in kwargs)
# Log pymoca version
logger.debug("Using pymoca {}.".format(pymoca.__version__))
# Transfer model from the Modelica .mo file to CasADi using pymoca
if 'model_name' in kwargs:
model_name = kwargs['model_name']
else:
if hasattr(self, 'model_name'):
model_name = self.model_name
else:
model_name = self.__class__.__name__
self.__pymoca_model = pymoca.backends.casadi.api.transfer_model(
kwargs['model_folder'], model_name, self.compiler_options())
# Extract the CasADi MX variables used in the model
self.__mx = {}
self.__mx['time'] = [self.__pymoca_model.time]
self.__mx['states'] = [v.symbol for v in self.__pymoca_model.states]
self.__mx['derivatives'] = [
v.symbol for v in self.__pymoca_model.der_states
]
self.__mx['algebraics'] = [
v.symbol for v in self.__pymoca_model.alg_states
]
self.__mx['parameters'] = [
v.symbol for v in self.__pymoca_model.parameters
]
self.__mx['control_inputs'] = []
self.__mx['constant_inputs'] = []
self.__mx['lookup_tables'] = []
# Merge with user-specified delayed feedback
delayed_feedback_variables = list(
map(lambda delayed_feedback: delayed_feedback[1],
self.delayed_feedback()))
for v in self.__pymoca_model.inputs:
if v.symbol.name() in delayed_feedback_variables:
# Delayed feedback variables are local to each ensemble, and
# therefore belong to the collection of algebraic variables,
# rather than to the control inputs.
self.__mx['algebraics'].append(v.symbol)
else:
if v.symbol.name() in kwargs.get('lookup_tables', []):
self.__mx['lookup_tables'].append(v.symbol)
elif v.fixed:
self.__mx['constant_inputs'].append(v.symbol)
else:
self.__mx['control_inputs'].append(v.symbol)
# Initialize nominals and types
# These are not in @cached dictionary properties for backwards compatibility.
self.__python_types = AliasDict(self.alias_relation)
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
self.__python_types[v.symbol.name()] = v.python_type
# Initialize dae and initial residuals
# These are not in @cached dictionary properties so that we need to create the list
# of function arguments only once.
variable_lists = [
'states', 'der_states', 'alg_states', 'inputs', 'constants',
'parameters'
]
function_arguments = [self.__pymoca_model.time] + [
ca.veccat(*[
v.symbol for v in getattr(self.__pymoca_model, variable_list)
]) for variable_list in variable_lists
]
self.__dae_residual = self.__pymoca_model.dae_residual_function(
*function_arguments)
if self.__dae_residual is None:
self.__dae_residual = ca.MX()
self.__initial_residual = self.__pymoca_model.initial_residual_function(
*function_arguments)
if self.__initial_residual is None:
self.__initial_residual = ca.MX()
# Log variables in debug mode
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("ModelicaMixin: Found states {}".format(', '.join(
[var.name() for var in self.__mx['states']])))
logger.debug("ModelicaMixin: Found derivatives {}".format(
', '.join([var.name() for var in self.__mx['derivatives']])))
logger.debug("ModelicaMixin: Found algebraics {}".format(', '.join(
[var.name() for var in self.__mx['algebraics']])))
logger.debug("ModelicaMixin: Found control inputs {}".format(
', '.join([var.name()
for var in self.__mx['control_inputs']])))
logger.debug("ModelicaMixin: Found constant inputs {}".format(
', '.join([var.name()
for var in self.__mx['constant_inputs']])))
logger.debug("ModelicaMixin: Found parameters {}".format(', '.join(
[var.name() for var in self.__mx['parameters']])))
# Call parent class first for default behaviour.
super().__init__(**kwargs)
@cached
def compiler_options(self) -> Dict[str, Union[str, bool]]:
"""
Subclasses can configure the `pymoca <http://github.com/pymoca/pymoca>`_ compiler options here.
:returns: A dictionary of pymoca compiler options. See the pymoca documentation for details.
"""
# Default options
compiler_options = {}
# Expand vector states to multiple scalar component states.
compiler_options['expand_vectors'] = True
# Where imported model libraries are located.
library_folders = self.modelica_library_folders.copy()
for ep in pkg_resources.iter_entry_points(
group='rtctools.libraries.modelica'):
if ep.name == "library_folder":
library_folders.append(
pkg_resources.resource_filename(ep.module_name,
ep.attrs[0]))
compiler_options['library_folders'] = library_folders
# Eliminate equations of the type 'var = const'.
compiler_options['eliminate_constant_assignments'] = True
# Eliminate constant symbols from model, replacing them with the values
# specified in the model.
compiler_options['replace_constant_values'] = True
# Replace any constant expressions into the model.
compiler_options['replace_constant_expressions'] = True
# Replace any parameter expressions into the model.
compiler_options['replace_parameter_expressions'] = True
# Eliminate variables starting with underscores.
compiler_options['eliminable_variable_expression'] = r'(.*[.]|^)_\w+\Z'
# Automatically detect and eliminate alias variables.
compiler_options['detect_aliases'] = True
# Cache the model on disk
compiler_options['cache'] = True
# Done
return compiler_options
def delayed_feedback(self):
delayed_feedback = super().delayed_feedback()
delayed_feedback.extend([(dfb.origin, dfb.name, dfb.delay)
for dfb in self.__pymoca_model.delayed_states
])
return delayed_feedback
@property
def dae_residual(self):
return self.__dae_residual
@property
def dae_variables(self):
return self.__mx
@property
@cached
def output_variables(self):
output_variables = [
ca.MX.sym(variable) for variable in self.__pymoca_model.outputs
]
output_variables.extend(self.__mx['control_inputs'])
return output_variables
@cached
def parameters(self, ensemble_member):
# Call parent class first for default values.
parameters = super().parameters(ensemble_member)
# Return parameter values from pymoca model
parameters.update(
{v.symbol.name(): v.value
for v in self.__pymoca_model.parameters})
# Done
return parameters
@cached
def constant_inputs(self, ensemble_member):
# Call parent class first for default values.
constant_inputs = super().constant_inputs(ensemble_member)
# Return input values from pymoca model
times = self.times()
constant_input_names = {
sym.name()
for sym in self.__mx['constant_inputs']
}
for v in self.__pymoca_model.inputs:
if v.symbol.name() in constant_input_names:
constant_inputs[v.symbol.name()] = Timeseries(
times, np.full_like(times, v.value))
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug(
"Read constant input {} = {} from Modelica model".
format(v.symbol.name(), v.value))
return constant_inputs
@cached
def initial_state(self, ensemble_member):
initial_state = AliasDict(self.alias_relation)
# Initial conditions obtained from start attributes.
for v in self.__pymoca_model.states:
if v.fixed:
initial_state[v.symbol.name()] = v.start
return initial_state
@property
def initial_residual(self):
return self.__initial_residual
@cached
def bounds(self):
# Call parent class first for default values.
bounds = super().bounds()
# Parameter values
parameters = self.parameters(0)
parameter_values = [
parameters.get(param.name(), param)
for param in self.__mx['parameters']
]
# Load additional bounds from model
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
sym_name = v.symbol.name()
try:
(m, M) = bounds[sym_name]
except KeyError:
if self.__python_types.get(sym_name, float) == bool:
(m, M) = (0, 1)
else:
(m, M) = (-np.inf, np.inf)
m_ = ca.MX(v.min)
if not m_.is_constant():
[m_] = substitute_in_external([m_], self.__mx['parameters'],
parameter_values)
if not m_.is_constant():
raise Exception(
'Could not resolve lower bound for variable {}'.format(
sym_name))
m_ = float(m_)
M_ = ca.MX(v.max)
if not M_.is_constant():
[M_] = substitute_in_external([M_], self.__mx['parameters'],
parameter_values)
if not M_.is_constant():
raise Exception(
'Could not resolve upper bound for variable {}'.format(
sym_name))
M_ = float(M_)
# We take the intersection of all provided bounds
m = max(m, m_)
M = min(M, M_)
bounds[sym_name] = (m, M)
return bounds
@cached
def seed(self, ensemble_member):
# Call parent class first for default values.
seed = super().seed(ensemble_member)
# Parameter values
parameters = self.parameters(0)
parameter_values = [
parameters.get(param.name(), param)
for param in self.__mx['parameters']
]
# Load seeds
for var in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states):
start = ca.MX(var.start)
if not var.fixed and not start.is_zero():
# If start contains symbolics, try substituting parameter values
if not start.is_constant():
[start] = substitute_in_external([start],
self.__mx['parameters'],
parameter_values)
# If start is constant, seed it. Else, warn.
sym_name = var.symbol.name()
if start.is_constant():
times = self.times(sym_name)
start = var.python_type(var.start)
s = Timeseries(times, np.full_like(times, start))
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug(
"ModelicaMixin: Seeded variable {} = {}".format(
sym_name, start))
seed[sym_name] = s
else:
logger.error(
'ModelicaMixin: Could not resolve seed value for {}'.
format(sym_name))
return seed
def variable_is_discrete(self, variable):
return self.__python_types.get(variable, float) != float
@property
@cached
def alias_relation(self):
# Initialize aliases
alias_relation = AliasRelation()
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.der_states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
for alias in v.aliases:
alias_relation.add(v.symbol.name(), alias)
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("ModelicaMixin: Aliased {} to {}".format(
v.symbol.name(), alias))
return alias_relation
@property
@cached
def __nominals(self):
# Make the dict
nominal_dict = AliasDict(self.alias_relation)
# Grab parameters and their values
parameters = self.parameters(0)
parameter_values = [
parameters.get(param.name(), param)
for param in self.__mx['parameters']
]
# Iterate over nominalizable states
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
sym_name = v.symbol.name()
# For type consistency, cast to MX
nominal = ca.MX(v.nominal)
# If nominal contains parameter symbols, substitute them
if not nominal.is_constant():
[nominal] = substitute_in_external([nominal],
self.__mx['parameters'],
parameter_values)
if nominal.is_constant():
# Take absolute value (nominal sign is meaningless- a nominal is a magnitude)
nominal = ca.fabs(nominal)
# If nominal is 0 or 1, we just use the default (1.0)
if nominal.is_zero() or (nominal - 1).is_zero():
continue
# Cast to numpy array
nominal = nominal.to_DM().full().flatten()
try:
# Attempt to cast to python scalar before storing
nominal_dict[sym_name] = nominal.item()
except ValueError:
# Nominal is numpy array- store it as such
nominal_dict[sym_name] = nominal
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug(
"ModelicaMixin: Set nominal value for variable {} to {}"
.format(sym_name, nominal_dict[sym_name]))
else:
logger.warning(
"ModelicaMixin: Could not set nominal value for {}".format(
sym_name))
return nominal_dict
def variable_nominal(self, variable):
return self.__nominals.get(variable, 1)
def constant_inputs(self, ensemble_member):
# Constant inputs
return AliasDict(
self.alias_relation,
{'constant_input': Timeseries(self.times(), 1 - self.times())})
def pre(self):
# Call parent class first for default behaviour.
super().pre()
# rtcParameterConfig
self.__parameter_config = []
try:
for pi_parameter_config_basename in self.pi_parameter_config_basenames:
self.__parameter_config.append(
pi.ParameterConfig(self.__input_folder,
pi_parameter_config_basename))
except FileNotFoundError:
raise FileNotFoundError("PIMixin: {}.xml not found in {}.".format(
pi_parameter_config_basename, self.__input_folder))
# Make a parameters dict for later access
self.__parameters = {}
for parameter_config in self.__parameter_config:
for location_id, model_id, parameter_id, value in parameter_config:
try:
parameter = self.__data_config.parameter(
parameter_id, location_id, model_id)
except KeyError:
parameter = parameter_id
self.__parameters[parameter] = value
try:
self.__timeseries_import = pi.Timeseries(
self.__data_config,
self.__input_folder,
self.timeseries_import_basename,
binary=self.pi_binary_timeseries,
pi_validate_times=self.pi_validate_timeseries)
except FileNotFoundError:
raise FileNotFoundError('PIMixin: {}.xml not found in {}'.format(
self.timeseries_import_basename, self.__input_folder))
self.__timeseries_export = pi.Timeseries(
self.__data_config,
self.__output_folder,
self.timeseries_export_basename,
binary=self.pi_binary_timeseries,
pi_validate_times=False,
make_new_file=True)
# Convert timeseries timestamps to seconds since t0 for internal use
self.__timeseries_import_times = self.__datetime_to_sec(
self.__timeseries_import.times)
# Timestamp check
if self.pi_validate_timeseries:
for i in range(len(self.__timeseries_import_times) - 1):
if self.__timeseries_import_times[
i] >= self.__timeseries_import_times[i + 1]:
raise ValueError(
'PIMixin: Time stamps must be strictly increasing.')
# Check if the timeseries are equidistant
self.__dt = self.__timeseries_import_times[
1] - self.__timeseries_import_times[0]
if self.pi_validate_timeseries:
for i in range(len(self.__timeseries_import_times) - 1):
if self.__timeseries_import_times[
i +
1] - self.__timeseries_import_times[i] != self.__dt:
raise ValueError(
'PIMixin: Expecting equidistant timeseries, the time step '
'towards {} is not the same as the time step(s) before. Set '
'unit to nonequidistant if this is intended.'.format(
self.__timeseries_import.times[i + 1]))
# Stick timeseries into an AliasDict
self.__timeseries_import_dict = AliasDict(self.alias_relation)
debug = logger.getEffectiveLevel() == logging.DEBUG
for variable, values in self.__timeseries_import.items():
if debug and self.__timeseries_import_dict.get(variable,
None) is not None:
logger.debug(
'PIMixin: Timeseries {} replaced another aliased timeseries.'
.format(variable))
self.__timeseries_import_dict[variable] = values
class PIMixin(SimulationProblem):
"""
Adds `Delft-FEWS Published Interface
<https://publicwiki.deltares.nl/display/FEWSDOC/The+Delft-Fews+Published+Interface>`_
I/O to your simulation problem.
During preprocessing, files named ``rtcDataConfig.xml``, ``timeseries_import.xml``, and``rtcParameterConfig.xml``
are read from the ``input`` subfolder. ``rtcDataConfig.xml`` maps
tuples of FEWS identifiers, including location and parameter ID, to RTC-Tools time series identifiers.
During postprocessing, a file named ``timeseries_export.xml`` is written to the ``output`` subfolder.
:cvar pi_binary_timeseries: Whether to use PI binary timeseries format. Default is ``False``.
:cvar pi_parameter_config_basenames:
List of parameter config file basenames to read. Default is [``rtcParameterConfig``].
:cvar pi_check_for_duplicate_parameters: Check if duplicate parameters are read. Default is ``False``.
:cvar pi_validate_timeseries: Check consistency of timeseries. Default is ``True``.
"""
#: Whether to use PI binary timeseries format
pi_binary_timeseries = False
#: Location of rtcParameterConfig files
pi_parameter_config_basenames = ['rtcParameterConfig']
#: Check consistency of timeseries
pi_validate_timeseries = True
#: Check for duplicate parameters
pi_check_for_duplicate_parameters = True
# Default names for timeseries I/O
timeseries_import_basename = 'timeseries_import'
timeseries_export_basename = 'timeseries_export'
def __init__(self, **kwargs):
# Check arguments
assert ('input_folder' in kwargs)
assert ('output_folder' in kwargs)
# Save arguments
self.__input_folder = kwargs['input_folder']
self.__output_folder = kwargs['output_folder']
# Load rtcDataConfig.xml. We assume this file does not change over the
# life time of this object.
self.__data_config = rtc.DataConfig(self.__input_folder)
# Call parent class first for default behaviour.
super().__init__(**kwargs)
def pre(self):
# Call parent class first for default behaviour.
super().pre()
# rtcParameterConfig
self.__parameter_config = []
try:
for pi_parameter_config_basename in self.pi_parameter_config_basenames:
self.__parameter_config.append(
pi.ParameterConfig(self.__input_folder,
pi_parameter_config_basename))
except FileNotFoundError:
raise FileNotFoundError("PIMixin: {}.xml not found in {}.".format(
pi_parameter_config_basename, self.__input_folder))
# Make a parameters dict for later access
self.__parameters = {}
for parameter_config in self.__parameter_config:
for location_id, model_id, parameter_id, value in parameter_config:
try:
parameter = self.__data_config.parameter(
parameter_id, location_id, model_id)
except KeyError:
parameter = parameter_id
self.__parameters[parameter] = value
try:
self.__timeseries_import = pi.Timeseries(
self.__data_config,
self.__input_folder,
self.timeseries_import_basename,
binary=self.pi_binary_timeseries,
pi_validate_times=self.pi_validate_timeseries)
except FileNotFoundError:
raise FileNotFoundError('PIMixin: {}.xml not found in {}'.format(
self.timeseries_import_basename, self.__input_folder))
self.__timeseries_export = pi.Timeseries(
self.__data_config,
self.__output_folder,
self.timeseries_export_basename,
binary=self.pi_binary_timeseries,
pi_validate_times=False,
make_new_file=True)
# Convert timeseries timestamps to seconds since t0 for internal use
self.__timeseries_import_times = self.__datetime_to_sec(
self.__timeseries_import.times)
# Timestamp check
if self.pi_validate_timeseries:
for i in range(len(self.__timeseries_import_times) - 1):
if self.__timeseries_import_times[
i] >= self.__timeseries_import_times[i + 1]:
raise ValueError(
'PIMixin: Time stamps must be strictly increasing.')
# Check if the timeseries are equidistant
self.__dt = self.__timeseries_import_times[
1] - self.__timeseries_import_times[0]
if self.pi_validate_timeseries:
for i in range(len(self.__timeseries_import_times) - 1):
if self.__timeseries_import_times[
i +
1] - self.__timeseries_import_times[i] != self.__dt:
raise ValueError(
'PIMixin: Expecting equidistant timeseries, the time step '
'towards {} is not the same as the time step(s) before. Set '
'unit to nonequidistant if this is intended.'.format(
self.__timeseries_import.times[i + 1]))
# Stick timeseries into an AliasDict
self.__timeseries_import_dict = AliasDict(self.alias_relation)
debug = logger.getEffectiveLevel() == logging.DEBUG
for variable, values in self.__timeseries_import.items():
if debug and self.__timeseries_import_dict.get(variable,
None) is not None:
logger.debug(
'PIMixin: Timeseries {} replaced another aliased timeseries.'
.format(variable))
self.__timeseries_import_dict[variable] = values
def initialize(self, config_file=None):
# Set up experiment
self.setup_experiment(0, self.__timeseries_import_times[-1], self.__dt)
# Load parameters from parameter config
self.__parameter_variables = set(self.get_parameter_variables())
logger.debug("Model parameters are {}".format(
self.__parameter_variables))
for parameter, value in self.__parameters.items():
if parameter in self.__parameter_variables:
logger.debug("PIMixin: Setting parameter {} = {}".format(
parameter, value))
self.set_var(parameter, value)
# Load input variable names
self.__input_variables = set(self.get_input_variables().keys())
# Set input values
for variable in self.__input_variables:
value = self.__timeseries_import_dict[variable][
self.__timeseries_import.forecast_index]
if np.isfinite(value):
self.set_var(variable, value)
else:
logger.debug(
'PIMixin: Found bad value {} at index [{}] in timeseries aliased to input {}'
.format(value, self.__timeseries_import.forecast_index,
variable))
logger.debug("Model inputs are {}".format(self.__input_variables))
# Empty output
self.__output_variables = self.get_output_variables()
n_times = len(self.__timeseries_import_times)
self.__output = AliasDict(self.alias_relation)
self.__output.update({
variable: np.full(n_times, np.nan)
for variable in self.__output_variables
})
# Call super, which will also initialize the model itself
super().initialize(config_file)
# Extract consistent t0 values
for variable in self.__output_variables:
self.__output[variable][self.__timeseries_import.
forecast_index] = self.get_var(variable)
def update(self, dt):
# Time step
if dt < 0:
dt = self.__dt
# Current time stamp
t = self.get_current_time()
# Get current time index
t_idx = bisect.bisect_left(self.__timeseries_import_times, t + dt)
# Set input values
for variable in self.__input_variables:
value = self.__timeseries_import_dict[variable][t_idx]
if np.isfinite(value):
self.set_var(variable, value)
else:
logger.debug(
'PIMixin: Found bad value {} at index [{}] in timeseries aliased to input {}'
.format(value, t_idx, variable))
# Call super
super().update(dt)
# Extract results
for variable in self.__output_variables:
self.__output[variable][t_idx] = self.get_var(variable)
def post(self):
# Call parent class first for default behaviour.
super().post()
# Start of write output
# Write the time range for the export file.
self.__timeseries_export.times = self.__timeseries_import.times[
self.__timeseries_import.forecast_index:]
# Write other time settings
self.__timeseries_export.forecast_datetime = self.__timeseries_import.forecast_datetime
self.__timeseries_export.dt = self.__timeseries_import.dt
self.__timeseries_export.timezone = self.__timeseries_import.timezone
# Write the ensemble properties for the export file.
self.__timeseries_export.ensemble_size = 1
self.__timeseries_export.contains_ensemble = self.__timeseries_import.contains_ensemble
# For all variables that are output variables the values are
# extracted from the results.
for variable in self.__output_variables:
values = self.__output[variable]
# Check if ID mapping is present
try:
self.__data_config.pi_variable_ids(variable)
except KeyError:
logger.debug(
'PIMixin: variable {} has no mapping defined in rtcDataConfig '
'so cannot be added to the output file.'.format(variable))
continue
# Add series to output file
self.__timeseries_export.set(
variable,
values,
unit=self.__timeseries_import.get_unit(variable))
# Write output file to disk
self.__timeseries_export.write()
def __datetime_to_sec(self, d):
# Return the date/timestamps in seconds since t0.
if hasattr(d, '__iter__'):
return np.array([
(t -
self.__timeseries_import.forecast_datetime).total_seconds()
for t in d
])
else:
return (
d -
self.__timeseries_import.forecast_datetime).total_seconds()
def __sec_to_datetime(self, s):
# Return the date/timestamps in seconds since t0 as datetime objects.
if hasattr(s, '__iter__'):
return [
self.__timeseries_import.forecast_datetime +
timedelta(seconds=t) for t in s
]
else:
return self.__timeseries_import.forecast_datetime + timedelta(
seconds=s)
@cached
def parameters(self):
"""
Return a dictionary of parameters, including parameters in PI Parameter Config XML files.
:returns: Dictionary of parameters
"""
# Call parent class first for default values.
parameters = super().parameters()
# Load parameters from parameter config
parameters.update(self.__parameters)
if logger.getEffectiveLevel() == logging.DEBUG:
for parameter in self.__parameters:
logger.debug("CSVMixin: Read parameter {} ".format(parameter))
return parameters
@cached
def times(self, variable=None):
"""
Return a list of all the timesteps in seconds.
:param variable: Variable name.
:returns: A list of all the timesteps in seconds.
"""
return self.__timeseries_import_times[self.__timeseries_import.
forecast_index:]
def timeseries_at(self, variable, t):
"""
Return the value of a time series at the given time.
:param variable: Variable name.
:param t: Time.
:returns: The interpolated value of the time series.
:raises: KeyError
"""
values = self.__timeseries_import_dict[variable]
t_idx = bisect.bisect_left(self.__timeseries_import_times, t)
if self.__timeseries_import_times[t_idx] == t:
return values[t_idx]
else:
return np.interp1d(t, self.__timeseries_import_times, values)
@property
def timeseries_import(self):
"""
:class:`pi.Timeseries` object containing the input data.
"""
return self.__timeseries_import
@property
def timeseries_import_times(self):
"""
List of time stamps for which input data is specified.
The time stamps are in seconds since t0, and may be negative.
"""
return self.__timeseries_import_times
@property
def timeseries_export(self):
"""
:class:`pi.Timeseries` object for holding the output data.
"""
return self.__timeseries_export
def set_timeseries(self,
variable,
values,
output=True,
check_consistency=True,
unit=None):
if check_consistency:
if len(self.times()) != len(values):
raise ValueError(
'PIMixin: Trying to set/append values {} with a different '
'length than the forecast length. Please make sure the '
'values cover forecastDate through endDate with timestep {}.'
.format(variable, self.__timeseries_import.dt))
if unit is None:
unit = self.__timeseries_import.get_unit(variable)
if output:
try:
self.__data_config.pi_variable_ids(variable)
except KeyError:
logger.debug(
'PIMixin: variable {} has no mapping defined in rtcDataConfig '
'so cannot be added to the output file.'.format(variable))
else:
self.__timeseries_export.set(variable, values, unit=unit)
self.__timeseries_import.set(variable, values, unit=unit)
self.__timeseries_import_dict[variable] = values
def get_timeseries(self, variable):
return self.__timeseries_import_dict[variable]
def extract_results(self):
"""
Extracts the results of output
:returns: An AliasDict of output variables and results array format.
"""
return self.__output
class SimulationProblem:
"""
Implements the `BMI <http://csdms.colorado.edu/wiki/BMI_Description>`_ Interface.
Base class for all Simulation problems. Loads the Modelica Model.
:cvar modelica_library_folders: Folders containing any referenced Modelica libraries. Default is an empty list.
"""
# Folders in which the referenced Modelica libraries are found
modelica_library_folders = []
def __init__(self, **kwargs):
# Check arguments
assert ('model_folder' in kwargs)
# Log pymoca version
logger.debug("Using pymoca {}.".format(pymoca.__version__))
# Transfer model from the Modelica .mo file to CasADi using pymoca
if 'model_name' in kwargs:
model_name = kwargs['model_name']
else:
if hasattr(self, 'model_name'):
model_name = self.model_name
else:
model_name = self.__class__.__name__
# Load model from pymoca backend
self.__pymoca_model = pymoca.backends.casadi.api.transfer_model(
kwargs['model_folder'], model_name, self.compiler_options())
# Extract the CasADi MX variables used in the model
self.__mx = {}
self.__mx['time'] = [self.__pymoca_model.time]
self.__mx['states'] = [v.symbol for v in self.__pymoca_model.states]
self.__mx['derivatives'] = [
v.symbol for v in self.__pymoca_model.der_states
]
self.__mx['algebraics'] = [
v.symbol for v in self.__pymoca_model.alg_states
]
self.__mx['parameters'] = [
v.symbol for v in self.__pymoca_model.parameters
]
self.__mx['constant_inputs'] = []
self.__mx['lookup_tables'] = []
# TODO: implement delayed feedback
delayed_feedback_variables = []
for v in self.__pymoca_model.inputs:
if v.symbol.name() in delayed_feedback_variables:
# Delayed feedback variables are local to each ensemble, and
# therefore belong to the collection of algebraic variables,
# rather than to the control inputs.
self.__mx['algebraics'].append(v.symbol)
else:
if v.symbol.name() in kwargs.get('lookup_tables', []):
self.__mx['lookup_tables'].append(v.symbol)
else:
# All inputs are constant inputs
self.__mx['constant_inputs'].append(v.symbol)
# Log variables in debug mode
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("SimulationProblem: Found states {}".format(', '.join(
[var.name() for var in self.__mx['states']])))
logger.debug("SimulationProblem: Found derivatives {}".format(
', '.join([var.name() for var in self.__mx['derivatives']])))
logger.debug("SimulationProblem: Found algebraics {}".format(
', '.join([var.name() for var in self.__mx['algebraics']])))
logger.debug("SimulationProblem: Found constant inputs {}".format(
', '.join([var.name()
for var in self.__mx['constant_inputs']])))
logger.debug("SimulationProblem: Found parameters {}".format(
', '.join([var.name() for var in self.__mx['parameters']])))
# Initialize an AliasDict for nominals and types
self.__nominals = AliasDict(self.alias_relation)
self.__python_types = AliasDict(self.alias_relation)
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
sym_name = v.symbol.name()
# Store the types in an AliasDict
self.__python_types[sym_name] = v.python_type
# If the nominal is 0.0 or 1.0 or -1.0, ignore: get_variable_nominal returns a default of 1.0
# TODO: handle nominal vectors (update() will need to load them)
if ca.MX(v.nominal).is_zero() or ca.MX(
v.nominal - 1).is_zero() or ca.MX(v.nominal + 1).is_zero():
continue
else:
if ca.MX(v.nominal).size1() != 1:
logger.error(
'Vector Nominals not supported yet. ({})'.format(
sym_name))
self.__nominals[sym_name] = ca.fabs(v.nominal)
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug(
"SimulationProblem: Setting nominal value for variable {} to {}"
.format(sym_name, self.__nominals[sym_name]))
# Initialize DAE and initial residuals
variable_lists = [
'states', 'der_states', 'alg_states', 'inputs', 'constants',
'parameters'
]
function_arguments = [self.__pymoca_model.time] + [
ca.veccat(*[
v.symbol for v in getattr(self.__pymoca_model, variable_list)
]) for variable_list in variable_lists
]
self.__dae_residual = self.__pymoca_model.dae_residual_function(
*function_arguments)
self.__initial_residual = self.__pymoca_model.initial_residual_function(
*function_arguments)
if self.__initial_residual is None:
self.__initial_residual = ca.MX()
# Construct state vector
self.__sym_list = self.__mx['states'] + self.__mx['algebraics'] + self.__mx['derivatives'] + \
self.__mx['time'] + self.__mx['constant_inputs'] + self.__mx['parameters']
self.__state_vector = np.full(len(self.__sym_list), np.nan)
# A very handy index
self.__states_end_index = len(self.__mx['states']) + \
len(self.__mx['algebraics']) + len(self.__mx['derivatives'])
# Construct a dict to look up symbols by name (or iterate over)
self.__sym_dict = OrderedDict(
((sym.name(), sym) for sym in self.__sym_list))
# Assemble some symbolics, including those needed for a backwards Euler derivative approximation
X = ca.vertcat(*self.__sym_list[:self.__states_end_index])
X_prev = ca.vertcat(*[
ca.MX.sym(sym.name() + '_prev')
for sym in self.__sym_list[:self.__states_end_index]
])
dt = ca.MX.sym("delta_t")
# Make a list of derivative approximations using backwards Euler formulation
derivative_approximation_residuals = []
for index, derivative_state in enumerate(self.__mx['derivatives']):
derivative_approximation_residuals.append(
derivative_state - (X[index] - X_prev[index]) / dt)
# Append residuals for derivative approximations
dae_residual = ca.vertcat(self.__dae_residual,
*derivative_approximation_residuals)
# TODO: implement lookup_tables
# 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():
index = self.__get_state_vector_index(sym_name)
# If the symbol is a state, Add the symbol to the lists
if index <= self.__states_end_index:
unscaled_symbols.append(X[index])
scaled_symbols.append(X[index] * nominal)
# Also scale previous states
unscaled_symbols.append(X_prev[index])
scaled_symbols.append(X_prev[index] * nominal)
# Substitute unscaled terms for scaled terms
dae_residual = ca.substitute(dae_residual,
ca.vertcat(*unscaled_symbols),
ca.vertcat(*scaled_symbols))
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug('SimulationProblem: DAE Residual is ' +
str(dae_residual))
if X.size1() != dae_residual.size1():
logger.error(
'Formulation Error: Number of states ({}) does not equal number of equations ({})'
.format(X.size1(), dae_residual.size1()))
# Construct function parameters
parameters = ca.vertcat(dt, X_prev,
*self.__sym_list[self.__states_end_index:])
# Construct a function res_vals that returns the numerical residuals of a numerical state
self.__res_vals = ca.Function("res_vals", [X, parameters],
[dae_residual])
# Use rootfinder() to make a function that takes a step forward in time by trying to zero res_vals()
options = {'nlpsol': 'ipopt', 'nlpsol_options': self.solver_options()}
self.__do_step = ca.rootfinder("next_state", "nlpsol", self.__res_vals,
options)
# Call parent class for default behaviour.
super().__init__()
def initialize(self, config_file=None):
"""
Initialize state vector with default values
:param config_file: Path to an initialization file.
"""
if config_file:
# TODO read start and stop time from config_file and call:
# self.setup_experiment(start,stop)
# for now, assume that setup_experiment was called beforehand
raise NotImplementedError
# Set values of parameters defined in the model into the state vector
for var in self.__pymoca_model.parameters:
# First check to see if parameter is already set (this allows child classes to override model defaults)
if np.isfinite(self.get_var(var.symbol.name())):
continue
# Also test to see if the value is constant
if isinstance(var.value, ca.MX) and not var.value.is_constant():
continue
# Try to extract the value
try:
# Extract the value as a python type
val = var.python_type(var.value)
except ValueError:
# var.value is a float NaN being cast to non-float
continue
else:
# If val is finite, we set it
if np.isfinite(val):
logger.debug(
'SimulationProblem: Setting parameter {} = {}'.format(
var.symbol.name(), val))
self.set_var(var.symbol.name(), val)
# 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.symbol.name()
var_nominal = self.get_variable_nominal(var_name)
# Attempt to cast var.start to python type
mx_start = ca.MX(var.start)
if mx_start.is_constant():
# cast var.start to python type
start_val = var.python_type(mx_start.to_DM())
else:
# var.start is a symbolic expression with unknown value
start_val = None
if start_val == 0.0 and not var.fixed:
# To make initialization easier, we allow setting initial states by providing timeseries
# with names that match a symbol in the model. We only check for this matching if the start
# and fixed attributes were left as default
try:
start_val = self.initial_state()[var_name]
except KeyError:
pass
else:
# An initial state was found- add it to the constrained residuals
logger.debug(
'Initialize: Added {} = {} to initial equations (found matching timeseries).'
.format(var_name, start_val))
# Set var to be fixed
var.fixed = True
# Attempt to set start_val in the state vector. Default to zero if unknown.
try:
self.set_var(var_name,
start_val if start_val is not None else 0.0)
except KeyError:
logger.warning(
'Initialize: {} not found in state vector. Initial value of {} not set.'
.format(var_name, start_val))
# Add a residual for the difference between the state and its starting expression
start_expr = start_val if start_val is not None else var.start
if var.fixed:
# require residual = 0
constrained_residuals.append(
(var.symbol - start_expr) / var_nominal)
else:
# minimize residual
minimized_residuals.append(
(var.symbol - start_expr) / var_nominal)
# Default start var for ders is zero
for der_var in self.__mx['derivatives']:
self.set_var(der_var.name(), 0.0)
# Warn for nans in state vector (verify we didn't miss anything)
self.__warn_for_nans()
# Optionally encourage a steady-state initial condition
if getattr(self, 'encourage_steady_state_initial_conditions', False):
# add penalty for der(var) != 0.0
for d in self.__mx['derivatives']:
logger.debug('Added {} to the minimized residuals.'.format(
d.name()))
minimized_residuals.append(d)
# Make minimized_residuals into a single symbolic object
minimized_residual = ca.vertcat(*minimized_residuals)
# Assemble symbolics needed to make a function describing the initial condition of the model
# We constrain every entry in this MX to zero
equality_constraints = ca.vertcat(self.__dae_residual,
self.__initial_residual,
*constrained_residuals)
# The variables that need a mutually consistent initial condition
X = ca.vertcat(*self.__sym_list[:self.__states_end_index])
# 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():
# Add the symbol to the lists
symbol = self.__sym_dict[sym_name]
unscaled_symbols.append(symbol)
scaled_symbols.append(symbol * nominal)
# Make the lists symbolic
unscaled_symbols = ca.vertcat(*unscaled_symbols)
scaled_symbols = ca.vertcat(*scaled_symbols)
# Substitute unscaled terms for scaled terms
equality_constraints = ca.substitute(equality_constraints,
unscaled_symbols, scaled_symbols)
minimized_residual = ca.substitute(minimized_residual,
unscaled_symbols, scaled_symbols)
logger.debug('SimulationProblem: Initial Equations are ' +
str(equality_constraints))
logger.debug('SimulationProblem: Minimized Residuals are ' +
str(minimized_residual))
# State bounds can be symbolic, written in terms of parameters. After all
# parameter values are known, we evaluate the numeric values of bounds.
symbolic_bounds = ca.vertcat(*[
ca.horzcat(v.min, v.max) for v in itertools.chain(
self.__pymoca_model.states, self.__pymoca_model.alg_states,
self.__pymoca_model.der_states)
])
bound_evaluator = ca.Function('bound_evaluator',
self.__mx['parameters'],
[symbolic_bounds])
# Evaluate bounds using values of parameters
n_parameters = len(self.__mx['parameters'])
if n_parameters > 0:
[evaluated_bounds
] = bound_evaluator.call(self.__state_vector[-n_parameters:])
else:
[evaluated_bounds] = bound_evaluator.call([])
# Construct arrays of state bounds (used in the initialize() nlp, but not in __do_step rootfinder)
self.__lbx = evaluated_bounds[:, 0]
self.__ubx = evaluated_bounds[:, 1]
# Constrain model equation residuals to zero
lbg = np.zeros(equality_constraints.size1())
ubg = np.zeros(equality_constraints.size1())
# Construct objective function from the input residual
objective_function = ca.dot(minimized_residual, minimized_residual)
# Construct nlp and solver to find initial state using ipopt
parameters = ca.vertcat(*self.__mx['time'],
*self.__mx['constant_inputs'],
*self.__mx['parameters'])
nlp = {
'x': X,
'f': objective_function,
'g': equality_constraints,
'p': parameters
}
solver = ca.nlpsol('solver', 'ipopt', nlp, self.solver_options())
# Construct guess
guess = ca.vertcat(
*np.nan_to_num(self.__state_vector[:self.__states_end_index]))
# Find initial state
initial_state = solver(x0=guess,
lbx=self.__lbx,
ubx=self.__ubx,
lbg=lbg,
ubg=ubg,
p=self.__state_vector[self.__states_end_index:])
# If unsuccessful, stop.
return_status = solver.stats()['return_status']
if return_status not in {
'Solve_Succeeded', 'Solved_To_Acceptable_Level'
}:
raise Exception(
'Initialization Failed with return status "{}"'.format(
return_status))
# Update state vector with initial conditions
self.__state_vector[:self.__states_end_index] = initial_state[
'x'][:self.__states_end_index].T
# make a copy of the initialized initial state vector in case we want to run the model again
self.__initialized_state_vector = copy.deepcopy(self.__state_vector)
# Warn for nans in state vector after initialization
self.__warn_for_nans()
def pre(self):
"""
Any preprocessing takes place here.
"""
pass
def post(self):
"""
Any postprocessing takes place here.
"""
pass
def setup_experiment(self, start, stop, dt):
"""
Method for subclasses (PIMixin, CSVMixin, or user classes) to set timing information for a simulation run.
:param start: Start time for the simulation.
:param stop: Final time for the simulation.
:param dt: Time step size.
"""
# Set class vars with start/stop/dt values
self.__start = start
self.__stop = stop
self.__dt = dt
# Set time in state vector
self.set_var('time', start)
def update(self, dt):
"""
Performs one timestep.
The methods ``setup_experiment`` and ``initialize`` must have been called before.
:param dt: Time step size.
"""
if dt < 0:
dt = self.__dt
logger.debug("Taking a step at {} with size {}".format(
self.get_current_time(), dt))
# increment time
self.set_var('time', self.get_current_time() + dt)
# take a step
guess = self.__state_vector[:self.__states_end_index]
next_state = self.__do_step(guess, ca.vertcat(dt,
*self.__state_vector))
# make sure that the step converged sufficiently
largest_res = ca.norm_inf(
self.__res_vals(next_state,
ca.vertcat(self.__dt, *self.__state_vector)))
tol = self.solver_options().get('ipopt.tol', 1.0e-8)
if largest_res > tol:
logger.warning(
'Simulation may have failed to converge at time {}. Residual value {} is greater than {}'
.format(self.get_current_time(), largest_res, tol))
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug('Residual maximum magnitude: {:.2E}'.format(
float(largest_res)))
# Update state vector
self.__state_vector[:self.__states_end_index] = next_state.T
def simulate(self):
"""
Run model from start_time to end_time.
"""
# Do any preprocessing, which may include changing parameter values on
# the model
logger.info("Preprocessing")
self.pre()
# Initialize model
logger.info("Initializing")
self.initialize()
# Perform all timesteps
logger.info("Running")
while self.get_current_time() < self.get_end_time():
self.update(-1)
# Do any postprocessing
logger.info("Postprocessing")
self.post()
def reset(self):
"""
Reset the FMU.
"""
self.__state_vector = copy.deepcopy(self.__initialized_state_vector)
def get_start_time(self):
"""
Return start time of experiment.
:returns: The start time of the experiment.
"""
return self.__start
def get_end_time(self):
"""
Return end time of experiment.
:returns: The end time of the experiment.
"""
return self.__stop
def get_current_time(self):
"""
Return current time of simulation.
:returns: The current simulation time.
"""
return self.get_var('time')
def get_time_step(self):
"""
Return simulation timestep.
:returns: The simulation timestep.
"""
return self.__dt
def get_var(self, name):
"""
Return a numpy array from FMU.
:param name: Variable name.
:returns: The value of the variable.
"""
# Get the canonical name and sign
name, sign = self.alias_relation.canonical_signed(name)
# Get the raw value of the canonical var
index = self.__get_state_vector_index(name)
value = self.__state_vector[index]
# Adjust sign if needed
if sign < 0:
value *= sign
# Adjust for nominal value if not default
nominal = self.get_variable_nominal(name)
if nominal != 1.0:
value *= nominal
return value
def get_var_count(self):
"""
Return the number of variables in the model.
:returns: The number of variables in the model.
"""
return len(self.get_variables())
def get_var_name(self, i):
"""
Returns the name of a variable.
:param i: Index in ordered dictionary returned by method get_variables.
:returns: The name of the variable.
"""
return list(self.get_variables())[i]
def get_var_type(self, name):
"""
Return type, compatible with numpy.
:param name: String variable name.
:returns: The numpy-compatible type of the variable.
:raises: KeyError
"""
return self.__python_types[name]
def get_var_rank(self, name):
"""
Not implemented
"""
raise NotImplementedError
def get_var_shape(self, name):
"""
Not implemented
"""
raise NotImplementedError
def get_variables(self):
"""
Return all variables (both internal and user defined)
:returns: An ordered dictionary of all variables supported by the model.
"""
return self.__sym_dict
@cached
def get_state_variables(self):
return AliasDict(
self.alias_relation, {
sym.name(): sym
for sym in (self.__mx['states'] + self.__mx['algebraics'])
})
@cached
def get_parameter_variables(self):
return AliasDict(self.alias_relation,
{sym.name(): sym
for sym in self.__mx['parameters']})
@cached
def get_input_variables(self):
return AliasDict(
self.alias_relation,
{sym.name(): sym
for sym in self.__mx['constant_inputs']})
@cached
def get_output_variables(self):
return self.__pymoca_model.outputs
@cached
def __get_state_vector_index(self, variable):
index = next((i for i, sym in enumerate(self.__sym_list)
if sym.name() == variable), None)
if index is None:
raise KeyError(str(variable) + " does not exist!")
return index
def __warn_for_nans(self):
"""
Test state vector for missing values and warn
"""
value_is_nan = np.isnan(self.__state_vector)
if any(value_is_nan):
for sym, isnan in zip(self.__sym_list, value_is_nan):
if isnan:
logger.warning('Variable {} has no value.'.format(sym))
def set_var(self, name, value):
"""
Set the value of the given variable.
:param name: Name of variable to set.
:param value: Value(s).
"""
# TODO: sanitize input
# Get the canonical name, adjust sign if needed
name, sign = self.alias_relation.canonical_signed(name)
if sign < 0:
value *= sign
# Adjust for nominal value if not default
nominal = self.get_variable_nominal(name)
if nominal != 1.0:
value /= nominal
# Store value in state vector
index = self.__get_state_vector_index(name)
self.__state_vector[index] = value
def set_var_slice(self, name, start, count, var):
"""
Not implemented.
"""
raise NotImplementedError
def set_var_index(self, name, index, var):
"""
Not implemented.
"""
raise NotImplementedError
def inq_compound(self, name):
"""
Not implemented.
"""
raise NotImplementedError
def inq_compound_field(self, name, index):
"""
Not implemented.
"""
raise NotImplementedError
def solver_options(self):
"""
Returns a dictionary of CasADi root_finder() solver options.
:returns: A dictionary of CasADi :class:`root_finder` options. See the CasADi documentation for details.
"""
return {'ipopt.print_level': 0, 'print_time': False}
def get_variable_nominal(self, variable):
"""
Get the value of the nominal attribute of a variable
"""
return self.__nominals.get(variable, 1.0)
def timeseries_at(self, variable, t):
"""
Get value of timeseries variable at time t: should be overridden by pi or csv mixin
"""
raise NotImplementedError
@cached
def initial_state(self) -> AliasDict:
"""
The initial state.
:returns: A dictionary of variable names and initial state (t0) values.
"""
t0 = self.get_start_time()
initial_state_dict = AliasDict(self.alias_relation)
for variable in list(self.get_state_variables()) + list(
self.get_input_variables()):
try:
initial_state_dict[variable] = self.timeseries_at(variable, t0)
except KeyError:
pass
except NotImplementedError:
pass
else:
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("Read intial state for {}".format(variable))
return initial_state_dict
@cached
def parameters(self):
"""
Return a dictionary of parameter values extracted from the Modelica model
"""
# Create AliasDict
parameters = AliasDict(self.alias_relation)
# Update with model parameters
parameters.update(
{p.symbol.name(): p.value
for p in self.__pymoca_model.parameters})
return parameters
@property
@cached
def alias_relation(self):
# Initialize aliases
alias_relation = AliasRelation()
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.der_states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
for alias in v.aliases:
alias_relation.add(v.symbol.name(), alias)
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("SimulationProblem: Aliased {} to {}".format(
v.symbol.name(), alias))
return alias_relation
@cached
def compiler_options(self):
"""
Subclasses can configure the `pymoca <http://github.com/pymoca/pymoca>`_ compiler options here.
:returns: A dictionary of pymoca compiler options. See the pymoca documentation for details.
"""
# Default options
compiler_options = {}
# Expand vector states to multiple scalar component states.
compiler_options['expand_vectors'] = True
# Where imported model libraries are located.
library_folders = self.modelica_library_folders.copy()
for ep in pkg_resources.iter_entry_points(
group='rtctools.libraries.modelica'):
if ep.name == "library_folder":
library_folders.append(
pkg_resources.resource_filename(ep.module_name,
ep.attrs[0]))
compiler_options['library_folders'] = library_folders
# Eliminate equations of the type 'var = const'.
compiler_options['eliminate_constant_assignments'] = True
# Eliminate constant symbols from model, replacing them with the values
# specified in the model.
compiler_options['replace_constant_values'] = True
# Replace any constant expressions into the model.
compiler_options['replace_constant_expressions'] = True
# Replace any parameter expressions into the model.
compiler_options['replace_parameter_expressions'] = True
# Eliminate variables starting with underscores.
compiler_options['eliminable_variable_expression'] = r'(.*[.]|^)_\w+\Z'
# Automatically detect and eliminate alias variables.
compiler_options['detect_aliases'] = True
# Cache the model on disk
compiler_options['cache'] = True
# Done
return compiler_options
def __init__(self, **kwargs):
# Check arguments
assert ('model_folder' in kwargs)
# Log pymoca version
logger.debug("Using pymoca {}.".format(pymoca.__version__))
# Transfer model from the Modelica .mo file to CasADi using pymoca
if 'model_name' in kwargs:
model_name = kwargs['model_name']
else:
if hasattr(self, 'model_name'):
model_name = self.model_name
else:
model_name = self.__class__.__name__
# Load model from pymoca backend
self.__pymoca_model = pymoca.backends.casadi.api.transfer_model(
kwargs['model_folder'], model_name, self.compiler_options())
# Extract the CasADi MX variables used in the model
self.__mx = {}
self.__mx['time'] = [self.__pymoca_model.time]
self.__mx['states'] = [v.symbol for v in self.__pymoca_model.states]
self.__mx['derivatives'] = [
v.symbol for v in self.__pymoca_model.der_states
]
self.__mx['algebraics'] = [
v.symbol for v in self.__pymoca_model.alg_states
]
self.__mx['parameters'] = [
v.symbol for v in self.__pymoca_model.parameters
]
self.__mx['constant_inputs'] = []
self.__mx['lookup_tables'] = []
# TODO: implement delayed feedback
delayed_feedback_variables = []
for v in self.__pymoca_model.inputs:
if v.symbol.name() in delayed_feedback_variables:
# Delayed feedback variables are local to each ensemble, and
# therefore belong to the collection of algebraic variables,
# rather than to the control inputs.
self.__mx['algebraics'].append(v.symbol)
else:
if v.symbol.name() in kwargs.get('lookup_tables', []):
self.__mx['lookup_tables'].append(v.symbol)
else:
# All inputs are constant inputs
self.__mx['constant_inputs'].append(v.symbol)
# Log variables in debug mode
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug("SimulationProblem: Found states {}".format(', '.join(
[var.name() for var in self.__mx['states']])))
logger.debug("SimulationProblem: Found derivatives {}".format(
', '.join([var.name() for var in self.__mx['derivatives']])))
logger.debug("SimulationProblem: Found algebraics {}".format(
', '.join([var.name() for var in self.__mx['algebraics']])))
logger.debug("SimulationProblem: Found constant inputs {}".format(
', '.join([var.name()
for var in self.__mx['constant_inputs']])))
logger.debug("SimulationProblem: Found parameters {}".format(
', '.join([var.name() for var in self.__mx['parameters']])))
# Initialize an AliasDict for nominals and types
self.__nominals = AliasDict(self.alias_relation)
self.__python_types = AliasDict(self.alias_relation)
for v in itertools.chain(self.__pymoca_model.states,
self.__pymoca_model.alg_states,
self.__pymoca_model.inputs):
sym_name = v.symbol.name()
# Store the types in an AliasDict
self.__python_types[sym_name] = v.python_type
# If the nominal is 0.0 or 1.0 or -1.0, ignore: get_variable_nominal returns a default of 1.0
# TODO: handle nominal vectors (update() will need to load them)
if ca.MX(v.nominal).is_zero() or ca.MX(
v.nominal - 1).is_zero() or ca.MX(v.nominal + 1).is_zero():
continue
else:
if ca.MX(v.nominal).size1() != 1:
logger.error(
'Vector Nominals not supported yet. ({})'.format(
sym_name))
self.__nominals[sym_name] = ca.fabs(v.nominal)
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug(
"SimulationProblem: Setting nominal value for variable {} to {}"
.format(sym_name, self.__nominals[sym_name]))
# Initialize DAE and initial residuals
variable_lists = [
'states', 'der_states', 'alg_states', 'inputs', 'constants',
'parameters'
]
function_arguments = [self.__pymoca_model.time] + [
ca.veccat(*[
v.symbol for v in getattr(self.__pymoca_model, variable_list)
]) for variable_list in variable_lists
]
self.__dae_residual = self.__pymoca_model.dae_residual_function(
*function_arguments)
self.__initial_residual = self.__pymoca_model.initial_residual_function(
*function_arguments)
if self.__initial_residual is None:
self.__initial_residual = ca.MX()
# Construct state vector
self.__sym_list = self.__mx['states'] + self.__mx['algebraics'] + self.__mx['derivatives'] + \
self.__mx['time'] + self.__mx['constant_inputs'] + self.__mx['parameters']
self.__state_vector = np.full(len(self.__sym_list), np.nan)
# A very handy index
self.__states_end_index = len(self.__mx['states']) + \
len(self.__mx['algebraics']) + len(self.__mx['derivatives'])
# Construct a dict to look up symbols by name (or iterate over)
self.__sym_dict = OrderedDict(
((sym.name(), sym) for sym in self.__sym_list))
# Assemble some symbolics, including those needed for a backwards Euler derivative approximation
X = ca.vertcat(*self.__sym_list[:self.__states_end_index])
X_prev = ca.vertcat(*[
ca.MX.sym(sym.name() + '_prev')
for sym in self.__sym_list[:self.__states_end_index]
])
dt = ca.MX.sym("delta_t")
# Make a list of derivative approximations using backwards Euler formulation
derivative_approximation_residuals = []
for index, derivative_state in enumerate(self.__mx['derivatives']):
derivative_approximation_residuals.append(
derivative_state - (X[index] - X_prev[index]) / dt)
# Append residuals for derivative approximations
dae_residual = ca.vertcat(self.__dae_residual,
*derivative_approximation_residuals)
# TODO: implement lookup_tables
# 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():
index = self.__get_state_vector_index(sym_name)
# If the symbol is a state, Add the symbol to the lists
if index <= self.__states_end_index:
unscaled_symbols.append(X[index])
scaled_symbols.append(X[index] * nominal)
# Also scale previous states
unscaled_symbols.append(X_prev[index])
scaled_symbols.append(X_prev[index] * nominal)
# Substitute unscaled terms for scaled terms
dae_residual = ca.substitute(dae_residual,
ca.vertcat(*unscaled_symbols),
ca.vertcat(*scaled_symbols))
if logger.getEffectiveLevel() == logging.DEBUG:
logger.debug('SimulationProblem: DAE Residual is ' +
str(dae_residual))
if X.size1() != dae_residual.size1():
logger.error(
'Formulation Error: Number of states ({}) does not equal number of equations ({})'
.format(X.size1(), dae_residual.size1()))
# Construct function parameters
parameters = ca.vertcat(dt, X_prev,
*self.__sym_list[self.__states_end_index:])
# Construct a function res_vals that returns the numerical residuals of a numerical state
self.__res_vals = ca.Function("res_vals", [X, parameters],
[dae_residual])
# Use rootfinder() to make a function that takes a step forward in time by trying to zero res_vals()
options = {'nlpsol': 'ipopt', 'nlpsol_options': self.solver_options()}
self.__do_step = ca.rootfinder("next_state", "nlpsol", self.__res_vals,
options)
# Call parent class for default behaviour.
super().__init__()
def get_input_variables(self):
return AliasDict(
self.alias_relation,
{sym.name(): sym
for sym in self.__mx['constant_inputs']})
def get_parameter_variables(self):
return AliasDict(self.alias_relation,
{sym.name(): sym
for sym in self.__mx['parameters']})