Simulate an FMU

The otfmi simulate function instanciates, initializes and simulates the FMU.

First, retrieve and load the FMU deviation.fmu.

import openturns as ot
import otfmi.example.utility
import matplotlib.pyplot as plt

path_fmu = otfmi.example.utility.get_path_fmu("deviation")
model = otfmi.fmi.load_fmu(path_fmu)

Note

model is a PyFMI object, loaded with otfmi’s overlay.

As such, model.simulate() is a pure PyFMI method.

Use otfmi.fmi.simulate(model) to benefit from otfmi’s overlay.

otfmi simulate function notably eases initializing a FMU, see Initialize an FMU with non-default values.

On top of the initialization keywords, PyFMI simulation keywords can be employed:

result = otfmi.fmi.simulate(
    model,
    start_time=0,  # PyFMI keyword
    final_time=1,  # PyFMI keyword
    initialization_parameters=(["L"], [300]),
)  # otfmi keyword
print("y = %g" % result.final("y"))

Simulation interval    : 0 - 1.0 seconds.
Elapsed simulation time: 0.012806855999997424 seconds.
y = 22.5

We can use these keyword to plot the deviation Y as function of the beam length L:

inputSample = ot.RegularGrid(1.0, 10.0, 10).getValues()

list_output = []
for length in inputSample:
    result = otfmi.fmi.simulate(model, initialization_parameters=(["L"], [length]))
    list_output.append(result.final("y"))
outputSample = ot.Sample([[xx] for xx in list_output])

plt.figure()
plt.plot(inputSample, outputSample)
plt.show()

Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012459750000004988 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012480698999979722 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012462284000008594 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012675230000013471 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012560718000003135 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012581146000002263 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012425635999989026 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012591826000004858 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012423302000001968 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012535871000011412 seconds.

The interest of the higher-level functions are:

- avoid the for loop on the points of the design of experiment,

- automatic formatting of the simulation outputs.