How to compile and simulate a modelica model that is part of a package with JModelica?

Question

My question is similar to the question of janpeter. I study the ebook by Tiller and try to simulate the example 'Architecture Driven Approach' with OpenModelica and JModelica. I tried the minimal example 'BaseSystem' in OpenModelica and it works fine. But with JModelica version 1.14 I get errors in the compiling process and my script fail. My python script is:

import matplotlib.pyplot as plt
from pymodelica import compile_fmu
from pyfmi import load_fmu

# Variables: modelName, modelFile, extraLibPath
modelName = 'BaseSystem'
modelFile = 'BaseSystem.mo'
extraLibPath = 'C:\Users\Tom\Desktop\Tiller2015a\ModelicaByExample\Architectures'
compilerOption = {'extra_lib_dirs':[extraLibPath]}

# Compile model
fmuName = compile_fmu( modelName, modelFile, compiler_options=compilerOption)

# Load model
model = load_fmu( fmuName)

# Simulate model
res = model.simulate( start_time=0.0, final_time=5.0)

# Extract interesting values
res_w = res['sensor.w']
res_y = res['setpoint.y']
tSim = res['time']

# Visualize results
fig = plt.figure(1)
ax1 = fig.add_subplot(111)
ax2 = ax1.twinx()
ax1.plot(tSim, res_w, 'g-')
ax2.plot(tSim, res_y, 'b-')
ax1.set_xlabel('t (s)')
ax1.set_ylabel('w (???)', color='g')
ax2.set_ylabel('y (???)', color='b')
plt.title('BaseSystem')
plt.legend()
plt.grid(True)
plt.show()

My problem is how to compile and simulate a model that is part of a package?

Answer 1

Thank you Michael Tiller. With your support I found the solution.

First, the modelName has to be full qualified. Second, as you mentioned, the extraLibPath should end at the top-level directory of the library ModelicaByExample. But then I got errors, that JModelica couldn't find components or declarations which are part of the Modelica Standard Library (MSL).

So I added the modelicaLibPath to the MSL, but the error messages remained the same. After many attempts, I launched the command line with administrator privileges and any errors were gone.

Here is the executable python script: BaseSystem.py

###  Attention!
# The script and/or the command line must be
# started with administrator privileges

import matplotlib.pyplot as plt
from pymodelica import compile_fmu
from pyfmi import load_fmu

# Variables: modelName, modelFile, extraLibPath
modelName = 'Architectures.SensorComparison.Examples.BaseSystem'
modelFile = ''
extraLibPath = 'C:\Users\Tom\Desktop\Tiller2015a\ModelicaByExample'
modelicaLibPath = 'C:\OpenModelica1.9.2\lib\omlibrary\Modelica 3.2.1'
compileToPath = 'C:\Users\Tom\Desktop\Tiller2015a'

# Set the compiler options
compilerOptions = {'extra_lib_dirs':[modelicaLibPath, extraLibPath]}

# Compile model
fmuName = compile_fmu( modelName, modelFile, compiler_options=compilerOptions, compile_to=compileToPath)

# Load model
model = load_fmu( fmuName)

# Simulate model
res = model.simulate( start_time=0.0, final_time=5.0)

# Extract interesting values
res_w = res['sensor.w']
res_y = res['setpoint.y']
tSim = res['time']

# Visualize results
fig = plt.figure(1)
ax1 = fig.add_subplot(111)
ax2 = ax1.twinx()
ax1.plot(tSim, res_w, 'g-')
ax2.plot(tSim, res_y, 'b-')
ax1.set_xlabel('t (s)')
ax1.set_ylabel('sensor.w (rad/s)', color='g')
ax2.set_ylabel('setpoint.y (rad/s)', color='b')
plt.title('BaseSystem')
plt.legend()
plt.grid(True)
plt.show()

Answer 2

I am not a jModelica user, but I think I see some confusion in your script. You wrote:

modelName = 'BaseSystem'
modelFile = 'BaseSystem.mo'
extraLibPath = 'C:\Users\Tom\Desktop\Tiller2015a\ModelicaByExample\Architectures'

But that implies (to me) that the compiler should open the package stored at C:\Users\Tom\Desktop\Tiller2015a\ModelicaByExample\Architectures. But the top-level package is ModelicaByExample and the model you want is Architectures.BaseSystem. So I think something like this is probably more appropriate:

modelName = 'Architectures.BaseSystem'
modelFile = 'package.mo'
extraLibPath = 'C:\Users\Tom\Desktop\Tiller2015a\ModelicaByExample'

The essential point here is that you should be opening ModelicaByExample (specifically, the package.mo file in the ModelicaByExample directory). That opens the ModelicaByExample package. You need to open this package because it is the top-level package. You can't load just a sub-package (which is what it looked like you were trying to do). Then, once you've got ModelicaByExample loaded, you can ask the compiler to specifically compile Architectures.BaseSystem.

I suspect OpenModelica was "helping" you by opening the top-level package anyway, even if you were asking it to open the sub-package.

But again, I don't know jModelica very well and I have definitely not tested any of these suggestions.