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 òtfmi.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: 0.010159051000016461 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: 0.010419696999974803 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010451155999987805 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010505286000011438 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010509583999976257 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010188976999984334 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010408606999988024 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010454632000005404 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.010422271999971144 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01029284000003372 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01006302199999709 seconds.

The interest of the higher-level functions TODO are:

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

- automatic formatting of the simulation outputs.