Plot in generated jupyter notebook not visible

[m-kessler]

With recent Jupyter versions the plots in the notebooks generated by the FMPy GUI are not displayed.

This is the notebook I get with fmpy 0.3.26 from the well known CoupledClutches FMU:

import fmpy
from fmpy import *

filename = 'CoupledClutches.fmu'

start_values = {
    # variable                                    start   unit      description
    'CoupledClutches1_T2':     (4.00000000000000000e-01, 's'),    # T2
    'CoupledClutches1_freqHz': (2.00000000000000000e-01, 'Hz'),   # freqHz
    'minsamplestep':           (2.50000000000000000e-02, 's'),    # Minimum time step between samples in binary data file
    'binfilename':                           'DISABLED',          # Name of binary data file
}

output = [
    'outputs[1]',  # J1.w
    'outputs[2]',  # J2.w
    'outputs[3]',  # J3.w
    'outputs[4]',  # J4.w
]

result = simulate_fmu(filename, start_values=start_values, output=output, stop_time=1.5)

plot_result(result)

The plot is not shown when this notebook is executed in Jupyter Lab 4.5.0.

The proposed solution from this answer on stackoverflow works.
After adding the following lines to the start of the notebook, the plot is visible:

import plotly.io as pio
pio.renderers.default = 'iframe'

[t-sommer]

@m-kessler, can you share the exact dependencies to reproduce the problem?

[m-kessler]

NOTE

This comment has been edited multiple times, as the situations appears to be more complex. Hence I added this note section above the updated answer in the section below.

Apparently the issue is related to uv/jupyterlab/plotly and it depends how you use jupyter lab with uv.

1. With the method Using Jupyter within a project the plot is not visible. See detailed steps in next section.
2. With Using Jupyter as a standalone tool everything works fine and the renderer needs no change:
   • Use this oneliner to start jupyter lab:

     uv tool run --with fmpy==0.3.26 --with plotly==6.5.0 jupyter lab
     

   • Now everything works fine

Steps to reproduce

Maybe I should have mentioned that I am running Jupyter lab via uv according to the uv documentation Using uv with Jupyter.

Here are the steps to hopefully reproduce the issue:

1. Create a new project with uv and add current versions of fmpy and plotly

uv init
uv add fmpy==0.3.26 plotly==6.5.0 

2. Run jupyter

uv run --with jupyter jupyter lab

3. Create a new notebook with the kernel Python 3 (ipykernel)

4. Add the code below which now contains the FMU download and the fixed plotly renderer:

# Notebook exported with FMPy 0.3.6 with added sections to fix plotting and get the FMU
import fmpy
from fmpy import *

# ----------- added -----------
import plotly.io as pio
# pio.renderers.default = 'iframe'
# ------------------------------

# ----------- added  -----------
# download the FMU and input file
def get_fmu():
    from fmpy.util import download_test_file
    import os.path
    for filename in ['CoupledClutches.fmu', 'CoupledClutches_in.csv']:
        if not os.path.isfile(filename):
            download_test_file('2.0', 'ModelExchange', 'MapleSim', '2016.2', 'CoupledClutches', filename)
get_fmu()
# ------------------------------

filename = 'CoupledClutches.fmu'

start_values = {
    # variable                                    start   unit      description
    'CoupledClutches1_T2':     (4.00000000000000000e-01, 's'),    # T2
    'CoupledClutches1_freqHz': (2.00000000000000000e-01, 'Hz'),   # freqHz
    'minsamplestep':           (2.50000000000000000e-02, 's'),    # Minimum time step between samples in binary data file
    'binfilename':                           'DISABLED',          # Name of binary data file
}

output = [
    'outputs[1]',  # J1.w
    'outputs[2]',  # J2.w
    'outputs[3]',  # J3.w
    'outputs[4]',  # J4.w
]

result = simulate_fmu(filename, start_values=start_values, output=output, stop_time=1.5)

plot_result(result)

With this code the plot is not displayed on my machine. Uncomment the added renderer line to fix it.