[bug] [plotting] Colorbar for Line Loading Not Displayed Correctly in pf_res_plotly

[TheBigFudge]

Bug report checklis

• Read the relevant sections of the documentation

• Searched the issues page for similar reports

• Browse the tutorials and tests for usefull code snippets and examples of use

• Reproduced the issue after updating with pip install --upgrade pandapower (or git pull)

• Tried basic troubleshooting (if a bug/error) like restarting the interpreter and checking the pythonpath

Reproducible Example

import pandapower as pp
import pandapower.networks as pn
from pandapower.plotting.plotly import pf_res_plotly

# Create a sample network
net = pn.mv_oberrhein()
pp.runpp(net)

# Plot the results
pf_res_plotly(net, filename='test.html')

Issue Description and Traceback

Description:
I am using pandapower==3.0 and plotly==6.0 to visualize power flow results with pf_res_plotly. However, the colormap legend for line loading does not appear correctly. I have tried different values for cpos_load, but the issue persists. The expected behavior is that the colorbar for line loading should be displayed correctly according to the climits_load range.

Steps to Reproduce:

1. Run a power flow calculation in a Pandapower network.
2. Use pf_res_plotly() to visualize the results.
3. Observe that the line loading colorbar is either missing or incorrectly positioned.

Observed Behavior:

• The colorbar does not appear correctly.
• Changing cpos_load does not fix the issue.
• The bus voltage legend is displayed correctly, but the loading map is missing.

see plot example

Expected Behavior

Expected Behavior:
The colorbar for line loading should be displayed at the correct position as defined by cpos_load.

Installed Versions

I have tested this with pandapower==3.0 and plotly==6.0.

also tested older version of plotly

Label

• Relevant labels are selected

[vogt31337]

@TheBigFudge plotly seems to have changed there js api and things are breaking. Could you by any chance try an earlier plotly version and check if this also happens?

[TheBigFudge]

hey! i have tried it with some plotly 5.X versions, but that didn't help. However, when I switched back to older pandapower version 2.14.x, both colour bars were visible again

[vogt31337]

I am currently experiencing similar issued, i think the internal conversion Routine does Not Like empty fields. I will probably soon build a Patch and repair this.