Scattergl points disappear when reaching a certain threshold in size difference

I noticed, that in Scattergl points start to disappear from the graph when resizing and reaching certain thresholds in size difference.

Minimal example:

from dash import Dash, html, dcc, callback
from dash.dependencies import Input, Output
import plotly.graph_objects as go
from plotly.graph_objs import Scattergl
import numpy as np
import pandas as pd


np.random.seed(41)
x = np.random.uniform(-10, 10, 10)
y = np.random.uniform(-10, 10, 10)
sizes = np.random.uniform(0, 1000, 10)

df = pd.DataFrame({
    'x': x,
    'y': y,
    'sizes': sizes
})

app = Dash(__name__)

app.layout = html.Div([
    dcc.Slider(min=13, max=14, value=1, id='slider-sizes', step=0.1),
    dcc.Graph(id='graph', style={"width": "100vw", "height": "80vh"}),
])


def update_marker_sizes(fig, size):
    for trace in fig.data:
        if 'marker' in trace and 'size' in trace.marker:
            trace.marker.size = [s * size for s in trace.marker.size]
    return fig


@callback(
    Output('graph', 'figure'),
    Input('slider-sizes', 'value')
)
def update_graph(size):
    figure = go.Figure(data=Scattergl(x=df["x"], y=df["y"], mode='markers',
                                      marker=dict(size=df['sizes']*size, sizemode='area')))
    print(f"{50*'-'}\nslider size:{size}")
    num_points = sum(
        len(trace['x']) for trace in figure.full_figure_for_development()['data'] if
        len(trace["x"]) > 1)
    print(f"num points in dev data (x): {num_points}")

    minsize, maxsize = float("inf"), float("-inf")
    for trace in figure.data:
        if hasattr(trace, 'marker') and hasattr(trace.marker, 'size'):
            if len(trace.marker.size) > 1:
                print(f"num points in data: {len(trace.marker.size)}")
            minsize = min(minsize, min(trace.marker.size))
            maxsize = max(maxsize, max(trace.marker.size))
    print(f"min: {minsize}, max: {maxsize}, diff: {maxsize - minsize}")

    return figure


if __name__ == '__main__':
    app.run_server(debug=True, port=8000)

The points are still present in the underlying data structure:

Output:

--------------------------------------------------
slider size:13.5
num points in dev data (x): 10
num points in data: 10
min: 1350.4235691765416, max: 10008.250444470288, diff: 8657.826875293747
--------------------------------------------------
slider size:13.6
num points in dev data (x): 10
num points in data: 10
min: 1360.4267067259975, max: 10082.385632947846, diff: 8721.958926221849
--------------------------------------------------
slider size:13.5
num points in dev data (x): 10
num points in data: 10
min: 1350.4235691765416, max: 10008.250444470288, diff: 8657.826875293747
--------------------------------------------------

Visually, this is what happens:

Commencez par exécuter l’exemple minimal de Dash fourni dans l’issue et faites varier le slider autour des seuils de taille signalés. Suivez le chemin de rendu de Scattergl afin de déterminer pourquoi des points disparaissent alors qu’ils sont toujours présents dans les données, puis vérifiez que tous les points restent visibles sur toute la plage de tailles permettant de reproduire le problème.