https://github.com/simonw/datasette-haversine

Datasette plugin that adds a custom SQL function for haversine distances
https://github.com/simonw/datasette-haversine

datasette datasette-io datasette-plugin

Last synced: 3 months ago
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Datasette plugin that adds a custom SQL function for haversine distances

• Host: GitHub
• URL: https://github.com/simonw/datasette-haversine
• Owner: simonw
• License: apache-2.0
• Created: 2019-10-24T05:16:14.000Z (about 5 years ago)
• Default Branch: main
• Last Pushed: 2023-12-29T18:04:33.000Z (about 1 year ago)
• Last Synced: 2024-10-06T20:53:21.456Z (3 months ago)
• Topics: datasette, datasette-io, datasette-plugin
• Language: Python
• Homepage:
• Size: 13.7 KB
• Stars: 2
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# datasette-haversine

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[![Tests](https://github.com/simonw/datasette-haversine/workflows/Test/badge.svg)](https://github.com/simonw/datasette-haversine/actions?query=workflow%3ATest)

[![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://github.com/simonw/datasette-haversine/blob/main/LICENSE)

Datasette plugin that adds a custom SQL function for haversine distances

Install this plugin in the same environment as Datasette to enable the `haversine()` SQL function.

```bash

datasette install datasette-haversine

```

The plugin is built on top of the [haversine](https://github.com/mapado/haversine) library.

## haversine() to calculate distances

```sql

select haversine(lat1, lon1, lat2, lon2);

```

This will return the distance in kilometers between the point defined by `(lat1, lon1)` and the point defined by `(lat2, lon2)`.

## Demo

You can try this function [here using Datasette Lite](https://lite.datasette.io/?install=datasette-haversine#/content?sql=select+haversine%28%0A++40.7128%2C+-74.0060%2C+--+New+York%0A++37.7749%2C+-122.4194%2C+--+San+Francisco%0A++%27mi%27%0A%29+as+distance_in_miles%3B).

```sql

select haversine(

  40.7128, -74.0060, -- New York

  37.7749, -122.4194, -- San Francisco

  'mi'

) as distance_in_miles;

```

## Custom units

By default `haversine()` returns results in km. You can pass an optional third argument to get results in a different unit:

- `ft` for feet

- `m` for meters

- `in` for inches

- `mi` for miles

- `nmi` for nautical miles

- `km` for kilometers (the default)

```sql

select haversine(lat1, lon1, lat2, lon2, 'mi');

```