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Animate point along line

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Animate a point

This source code of this example is adapted from the MapLibre GL JS example - Animate a point.

Uncomment the following line to install leafmap if needed.

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# %pip install "leafmap[maplibre]"

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import math
import time
import leafmap.maplibregl as leafmap

To run this notebook, you will need an API key from MapTiler. Once you have the API key, you can uncomment the following code block and replace YOUR_API_KEY with your actual API key. Then, run the code block code to set the API key as an environment variable.

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# import os
# os.environ["MAPTILER_KEY"] = "YOUR_API_KEY"

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def point_on_circle(angle, radius):
    return {
        "type": "Point",
        "coordinates": [math.cos(angle) * radius, math.sin(angle) * radius],
    }

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m = leafmap.Map(center=[0, 0], zoom=2, style="streets")
radius = 20
source = {"type": "geojson", "data": point_on_circle(0, radius)}
m.add_source("point", source)
layer = {
    "id": "point",
    "source": "point",
    "type": "circle",
    "paint": {"circle-radius": 10, "circle-color": "#007cbf"},
}
m.add_layer(layer)
m

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def animate_marker(duration, frame_rate, radius):
    start_time = time.time()
    while (time.time() - start_time) < duration:
        timestamp = (time.time() - start_time) * 1000  # Convert to milliseconds
        angle = timestamp / 1000  # Divisor controls the animation speed
        point = point_on_circle(angle, radius)
        m.set_data("point", point)
        # Wait for the next frame
        time.sleep(1 / frame_rate)

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duration = 10  # Duration of the animation in seconds
frame_rate = 30  # Frames per second

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animate_marker(duration, frame_rate, radius)