prevent scatter text overlap

[FilipMiscevic]

It would be useful to have a setting to exclude text labels from being graphed if they would overlap with other labels.

For instance, ggplot2 in R has a check_overlap parameter - when true, it produces a graph like this:

[nicolaskruchten]

See plotly/plotly.js#4674

[Karim-53]

One solution is to alternate the text position like in this live demo:

    import pandas as pd
    from plotly import express as px, graph_objects as go
    
    df = pd.DataFrame()
    df['x'] = [0, 1, 1, 2, 3, 6, 7, 7, 8, 8, 9, 9, 10, 11, 11, 12]
    df['y'] = [57, 55, 75, 23, 80, 66, 66, 23, 79, 79, 20, 71, 59, 74, 82, 77]
    df['explainer_name'] = ['tree_shap_approximation', 'saabas', 'tree_shap', 'baseline_random', 'archipelago',
                            'shapley_taylor_interaction', 'partition', 'anova', 'permutation_partition', 'permutation',
                            'shap_interaction', 'sage', 'maple', 'lime', 'kernel_shap', 'exact_shapley_values']
    
    fig = px.scatter(df,
                         x='x',
                         y='y',
                         # size='dot_size',
                         text='explainer_name',
                         # log_x=True,
                         labels={
                             "x": "Time",
                             "y": "Score",
                             # 'dot_size': 'Portability',
                             'explainer_name': 'Explainer '
                         },
                         title='No overlapping annotations',  # take some vertical space
                         )
    def improve_text_position(x):
        """ it is more efficient if the x values are sorted """
    positions = ['top center', 'bottom center']  # you can add more: left center ...
    return [positions[i % len(positions)] for i in range(len(x))]
    
    fig.update_traces(textposition=improve_text_position(df['x']))
    fig.show()

Before:

After:

It might not work with a lot of points but it should help many users :)