Add 3D choropleth notebook example (#819)

* Add 3D choropleth example

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docs/maplibre/3d_choropleth.ipynb

@@ -0,0 +1,130 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "[![image](https://jupyterlite.rtfd.io/en/latest/_static/badge.svg)](https://demo.leafmap.org/lab/index.html?path=maplibre/3d_choropleth.ipynb)\n",
+    "[![image](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/opengeos/leafmap/blob/master/docs/maplibre/3d_choropleth.ipynb)\n",
+    "[![image](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/opengeos/leafmap/HEAD)\n",
+    "\n",
+    "**Create a 3D choropleth map of Europe with countries extruded**\n",
+    "\n",
+    "This source code of this example is adapted from the MapTiler SDK JS example - [Create a 3D choropleth map of Europe with countries extruded](https://docs.maptiler.com/sdk-js/examples/fill-extrusion).\n",
+    "\n",
+    "Uncomment the following line to install [leafmap](https://leafmap.org) if needed."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# %pip install \"leafmap[maplibre]\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import leafmap.maplibregl as leafmap"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "To run this notebook, you will need an [API key](https://docs.maptiler.com/cloud/api/authentication-key/) from [MapTiler](https://www.maptiler.com/cloud/). 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."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# import os\n",
+    "# os.environ[\"MAPTILER_KEY\"] = \"YOUR_API_KEY\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "m = leafmap.Map(center=[19.43, 49.49], zoom=3, pitch=60, style=\"basic\")\n",
+    "source = {\n",
+    "    \"type\": \"geojson\",\n",
+    "    \"data\": \"https://docs.maptiler.com/sdk-js/assets/Mean_age_of_women_at_first_marriage_in_2019.geojson\",\n",
+    "}\n",
+    "m.add_source(\"countries\", source)\n",
+    "layer = {\n",
+    "    \"id\": \"eu-countries\",\n",
+    "    \"source\": \"countries\",\n",
+    "    \"type\": \"fill-extrusion\",\n",
+    "    \"paint\": {\n",
+    "        \"fill-extrusion-color\": [\n",
+    "            \"interpolate\",\n",
+    "            [\"linear\"],\n",
+    "            [\"get\", \"age\"],\n",
+    "            23.0,\n",
+    "            \"#fff5eb\",\n",
+    "            24.0,\n",
+    "            \"#fee6ce\",\n",
+    "            25.0,\n",
+    "            \"#fdd0a2\",\n",
+    "            26.0,\n",
+    "            \"#fdae6b\",\n",
+    "            27.0,\n",
+    "            \"#fd8d3c\",\n",
+    "            28.0,\n",
+    "            \"#f16913\",\n",
+    "            29.0,\n",
+    "            \"#d94801\",\n",
+    "            30.0,\n",
+    "            \"#8c2d04\",\n",
+    "        ],\n",
+    "        \"fill-extrusion-opacity\": 1,\n",
+    "        \"fill-extrusion-height\": [\"*\", [\"get\", \"age\"], 5000],\n",
+    "    },\n",
+    "}\n",
+    "first_symbol_layer_id = m.find_first_symbol_layer()[\"id\"]\n",
+    "m.add_layer(layer, first_symbol_layer_id)\n",
+    "m.add_layer_control()\n",
+    "m"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "![](https://i.imgur.com/fLgqYTa.png)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.11.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}

docs/maplibre/overview.md

@@ -16,6 +16,12 @@ Use extrusions to display buildings' height in 3D.
 
 [![](https://i.imgur.com/9QeicaE.png)](https://leafmap.org/maplibre/3d_buildings)
 
+## Create a 3D choropleth map
+
+Create a 3D choropleth map of Europe with countries extruded
+
+[![](https://i.imgur.com/fLgqYTa.png)](https://leafmap.org/maplibre/3d_choropleth)
+
 ## Extrude polygons for 3D indoor mapping
 
 Create a 3D indoor map with the fill-extrude-height paint property.

mkdocs.yml

@@ -141,6 +141,7 @@ nav:
     - MapLibre:
           - maplibre/overview.md
           - maplibre/3d_buildings.ipynb
+          - maplibre/3d_choropleth.ipynb
           - maplibre/3d_indoor_mapping.ipynb
           - maplibre/3d_style.ipynb
           - maplibre/3d_terrain.ipynb