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: 0.011109056999998757 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: 0.013701510000004191 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010876841000026616 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011017476000006354 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011202101999998604 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010948396000003413 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010866934000006268 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010833261000016137 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010806258999991769 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010964835999999423 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010796822000003203 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.