OpenLayers Heatmap¶

This notebook demonstrates the native OpenLayers heatmap layer for visualizing point density.

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# %pip install anymap-ts

# %pip install anymap-ts

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import json
import random
from anymap_ts import OpenLayersMap

import json import random from anymap_ts import OpenLayersMap

Generate Sample Point Data¶

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random.seed(42)
features = []
centers = [
    (-122.4, 37.8),
    (-118.2, 34.05),
    (-73.98, 40.75),
    (-87.63, 41.88),
    (-95.37, 29.76),
]

for cx, cy in centers:
    count = random.randint(80, 200)
    for _ in range(count):
        lng = cx + random.gauss(0, 0.3)
        lat = cy + random.gauss(0, 0.3)
        magnitude = random.uniform(1, 10)
        features.append(
            {
                "type": "Feature",
                "geometry": {"type": "Point", "coordinates": [lng, lat]},
                "properties": {"magnitude": magnitude},
            }
        )

point_data = {"type": "FeatureCollection", "features": features}
print(f"Generated {len(features)} points")

random.seed(42) features = [] centers = [ (-122.4, 37.8), (-118.2, 34.05), (-73.98, 40.75), (-87.63, 41.88), (-95.37, 29.76), ] for cx, cy in centers: count = random.randint(80, 200) for _ in range(count): lng = cx + random.gauss(0, 0.3) lat = cy + random.gauss(0, 0.3) magnitude = random.uniform(1, 10) features.append( { "type": "Feature", "geometry": {"type": "Point", "coordinates": [lng, lat]}, "properties": {"magnitude": magnitude}, } ) point_data = {"type": "FeatureCollection", "features": features} print(f"Generated {len(features)} points")

Basic Heatmap¶

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m = OpenLayersMap(center=[-98, 38], zoom=4, height="600px")
m.add_basemap("CartoDB.DarkMatter")
m.add_heatmap(
    point_data,
    name="heatmap",
    blur=20,
    radius=12,
    opacity=0.8,
)
m

m = OpenLayersMap(center=[-98, 38], zoom=4, height="600px") m.add_basemap("CartoDB.DarkMatter") m.add_heatmap( point_data, name="heatmap", blur=20, radius=12, opacity=0.8, ) m

Weighted Heatmap¶

Use a property as weight to control heatmap intensity.

In [ ]:

m = OpenLayersMap(center=[-98, 38], zoom=4, height="600px")
m.add_basemap("CartoDB.DarkMatter")
m.add_heatmap(
    point_data,
    name="weighted-heatmap",
    weight="magnitude",
    blur=25,
    radius=15,
    opacity=0.9,
)
m

m = OpenLayersMap(center=[-98, 38], zoom=4, height="600px") m.add_basemap("CartoDB.DarkMatter") m.add_heatmap( point_data, name="weighted-heatmap", weight="magnitude", blur=25, radius=15, opacity=0.9, ) m

Custom Gradient¶

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m = OpenLayersMap(center=[-98, 38], zoom=4, height="600px")
m.add_basemap("CartoDB.DarkMatter")
m.add_heatmap(
    point_data,
    name="custom-gradient",
    blur=20,
    radius=12,
    gradient=["#00f", "#0ff", "#0f0", "#ff0", "#f00"],
)
m

m = OpenLayersMap(center=[-98, 38], zoom=4, height="600px") m.add_basemap("CartoDB.DarkMatter") m.add_heatmap( point_data, name="custom-gradient", blur=20, radius=12, gradient=["#00f", "#0ff", "#0f0", "#ff0", "#f00"], ) m