https://github.com/iwpnd/tegola-cluster-points

Example on how to cluster points in PostGIS and serve via Tegola vector tiling service
https://github.com/iwpnd/tegola-cluster-points

postgis tegola

Last synced: 8 days ago
JSON representation

Example on how to cluster points in PostGIS and serve via Tegola vector tiling service

• Host: GitHub
• URL: https://github.com/iwpnd/tegola-cluster-points
• Owner: iwpnd
• License: mit
• Created: 2022-02-05T15:29:53.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2023-02-09T12:24:45.000Z (almost 2 years ago)
• Last Synced: 2024-12-08T19:36:13.266Z (14 days ago)
• Topics: postgis, tegola
• Language: PLpgSQL
• Homepage:
• Size: 6.84 KB
• Stars: 4
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# tegola-cluster-points

Example on how to cluster point data on different zoom levels.

## Idea

Following a discussion on tegola issue [#753](https://github.com/go-spatial/tegola/issues/753)

> Say you have a bunch of points in your provider. You create two layers.

> First layer uses the center point of a cluster as geometry field.

> Second layer uses the default geometry field of your points.

> Then building your map, you use the first layer with the center points of the clusters from zoom level x to y and the second layer from y to z.

## Usage

```

docker compose up

```

Generate 10.000 random points in a definied bounding box (here, Berlin).

See `sql/init.sql`.

```

PGPASSWORD=password psql \

    -U user \

    -h localhost \

    -p 5433 \

    -d points \

    -a \

    -f /sql/init.sql

```

Open the tegola viewer at `http://localhost/8080` and see the result.

## Gotcha

The example clusters points in a proximity of 0.001 degree to each other. This is appoximately 111m, depending on where you are at in the world. For better results use another CRS and change the `eps` distance value of the provider sql to your liking.

## License

MIT

## Maintainer

Benjamin Ramser - [@iwpnd](https://github.com/iwpnd). 

Project Link: [https://github.com/iwpnd/tegola-cluster-points](https://github.com/iwpnd/tegola-cluster-points)

## Acknowledgements

Ying Wang - [Generating random test data in PostGIS](https://bytes.yingw787.com/posts/2019/01/10/generating_randomized_postgis_data/)

Tegola - [tegola.io](https://tegola.io/)