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bokehholoviews

How to rotate text to be horizontal on Holoview with Bokeh

In the example in https://holoviews.org/gallery/demos/bokeh/route_chord.html , how can I change the orientation of the arc labels to be horizontal? Bonus points for not overlapping - or an alternative using a seperate legend

Solution

  • the answer courtesy of @philippjfr from gitter, was:

    # %%opts Chord [edge_color_index='SourceID' label_index='City' color_index='AirportID' width=800 height=800]
# %%opts Chord (cmap='Category20' edge_cmap='Category20')

def rotate_label(plot, element):
    text_cds = plot.handles['text_1_source']
    length = len(text_cds.data['angle'])
    text_cds.data['angle'] = [0]*length
    xs = text_cds.data['x']
    text = np.array(text_cds.data['text'])
    xs[xs<0] -= np.array([len(t)*0.019 for t in text[xs<0]])

busiest_airports.options(
    edge_color_index='SourceID', label_index='City', color_index='AirportID',
    width=800, height=800, finalize_hooks=[rotate_label], cmap='Category20',
    edge_cmap='Category20'
)