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: 0.013964565999998513 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: 0.013832587999985435 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01376393899997197 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01379125099998646 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013738601999989442 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013725407000009682 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013835774000000356 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01377731499999868 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013847145999989152 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013840072999983022 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.013772334999998748 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.