Support inverted label text option for Chord plot

ALL software version info

holoviews=1.13.3, bokeh=2.1.1

Description of expected behavior and the observed behavior

The label texts in the left half of the chord plot getting inverted.

It would be good if the default label text orientation can be made something like this image below:

Example code

import pandas as pd
import holoviews as hv
from holoviews import opts, dim
from bokeh.sampledata.les_mis import data

hv.extension('bokeh')
hv.output(size=300)

links = pd.DataFrame(data['links'])
nodes = hv.Dataset(pd.DataFrame(data['nodes']), 'index')
chord = hv.Chord((links, nodes)).select(value=(5, None))
chord.opts(
    opts.Chord(cmap='Category20', edge_cmap='Category20', edge_color=dim('source').str(), label_text_font_size='15px',
               labels='name', node_color=dim('index').str()))

[mullimanko]

I wrote a function to rotate the label text also for bokeh as backend. Not perfect, but maybe useful: https://stackoverflow.com/a/65610161

[mullimanko]

@janrygl, I tried your function and get the following error: WARNING:param.ChordPlot13794: Plotting hook <function rotate_label at 0x0000019D040C11F8> could not be applied:

‘labels’

– UPDATE –

janrygl’s solution only works by selecting matplotlib as plotting library backend with hv.extension("matplotlib"), which is not clear from his answer. Otherwise the above-mentioned error occurs.