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: 0.01296877800001539 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: 0.012815498999998454 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01290987699999846 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012871845999995912 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01278479199999083 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012692127999997638 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01285312100000624 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01267886299999077 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012764445000016167 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012790492999982916 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.012693991999981336 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.