Set FMU simulation parameters

FMUFunction is an OpenTURNS-friendly overlay of the class ÒpenTURNSFMUFunction, closer to the underlying PyFMI implementation. Some FMU simulation parameters can be given to FMUFunction, yet most of them can only be passed to an OpenTURNSFMUFunction.

---

First, retrieve the path to the FMU deviation.fmu. Recall the deviation model is static, i.e. its output does not evolve over time.

import otfmi.example.utility
import openturns as ot

path_fmu = otfmi.example.utility.get_path_fmu("deviation")

The FMU simulation final time is the only simulation-related parameter that can be passed to FMUFunction. This parameter is useless if the FMU is really time-independent (like this example); yet it can be come in use if the FMU requires time to converge.

function = otfmi.FMUFunction(
    path_fmu, inputs_fmu=["E", "I"], outputs_fmu=["y"], final_time=50.0
)

inputPoint = ot.Point([2e9, 7e7])
outputPoint = function(inputPoint)
print(outputPoint)

[1.11607e-06]

To set more parameters for the FMU simulation, OpenTURNSFMUFunction can be employed. Below, we set the start time for the simulation, the PyFMI algorithm running the simulation, and require simulation silent mode.

midlevel_function = otfmi.OpenTURNSFMUFunction(
    path_fmu, inputs_fmu=["E", "I"], outputs_fmu=["y"]
)

outputPoint = midlevel_function.simulate(
    inputPoint, start_time=10.0, algorithm="FMICSAlg", options={"silent_mode": True}
)

For advanced users, the middle-level class OpenTURNSFMUFunction also gives access to the PyFMI model. We can hence access all PyFMI’s object methods:

pyfmi_model = midlevel_function.model
print(dir(pyfmi_model))

['__class__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__ne__', '__new__', '__pyx_vtable__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setstate__', '__sizeof__', '__str__', '__subclasshook__', '_additional_logger', '_close_log_file', '_convert_filter', '_current_log_size', '_default_options', '_enable_logging', '_exec_algorithm', '_exec_estimate_algorithm', '_exec_simulate_algorithm', '_get', '_get_A', '_get_B', '_get_C', '_get_D', '_get_directional_proxy', '_get_time', '_group_A', '_group_B', '_group_C', '_group_D', '_has_entered_init_mode', '_invoked_dealloc', '_last_accepted_time', '_log_handler', '_log_is_stream', '_log_open', '_log_stream', '_log_stream_is_open', '_max_log_size', '_max_log_size_msg_sent', '_open_log_file', '_provides_directional_derivatives', '_pyEventInfo', '_relative_tolerance', '_result_file', '_save_bool_variables_val', '_save_int_variables_val', '_save_real_variables_val', '_set', '_set_log_stream', '_set_time', '_supports_get_set_FMU_state', 'append_log_message', 'cache', 'cancel_step', 'deserialize_fmu_state', 'do_step', 'enter_initialization_mode', 'estimate', 'estimate_options', 'exit_initialization_mode', 'extract_xml_log', 'file_object', 'free_fmu_state', 'free_instance', 'get', 'get_author', 'get_boolean', 'get_boolean_status', 'get_capability_flags', 'get_categories', 'get_copyright', 'get_default_experiment_start_time', 'get_default_experiment_step', 'get_default_experiment_stop_time', 'get_default_experiment_tolerance', 'get_derivatives_dependencies', 'get_derivatives_dependencies_kind', 'get_derivatives_list', 'get_description', 'get_directional_derivative', 'get_fmil_log_level', 'get_fmu_state', 'get_generation_date_and_time', 'get_generation_tool', 'get_guid', 'get_identifier', 'get_input_list', 'get_integer', 'get_integer_status', 'get_last_result_file', 'get_license', 'get_log', 'get_log_filename', 'get_log_level', 'get_max_log_size', 'get_model_time_varying_value_references', 'get_model_types_platform', 'get_model_variables', 'get_model_version', 'get_name', 'get_number_of_lines_log', 'get_ode_sizes', 'get_output_dependencies', 'get_output_dependencies_kind', 'get_output_derivatives', 'get_output_list', 'get_real', 'get_real_status', 'get_scalar_variable', 'get_state_space_representation', 'get_states_list', 'get_status', 'get_string', 'get_string_status', 'get_variable_alias', 'get_variable_alias_base', 'get_variable_by_valueref', 'get_variable_causality', 'get_variable_data_type', 'get_variable_declared_type', 'get_variable_description', 'get_variable_display_unit', 'get_variable_display_value', 'get_variable_initial', 'get_variable_max', 'get_variable_min', 'get_variable_naming_convention', 'get_variable_nominal', 'get_variable_references', 'get_variable_relative_quantity', 'get_variable_start', 'get_variable_unbounded', 'get_variable_unit', 'get_variable_valueref', 'get_variable_variability', 'get_version', 'has_reached_max_log_size', 'initialize', 'instantiate', 'print_log', 'reset', 'serialize_fmu_state', 'serialized_fmu_state_size', 'set', 'set_additional_logger', 'set_boolean', 'set_debug_logging', 'set_fmu_state', 'set_input_derivatives', 'set_integer', 'set_log_level', 'set_max_log_size', 'set_real', 'set_string', 'setup_experiment', 'simulate', 'simulate_options', 'terminate', 'time']

Note

Otfmi’ classes FMUFunction and OpenTURNSFMUFunction are designed to highlight the most useful PyFMI’s methods and simplify their use!