https://github.com/bsm/geohashi

Go(lang) clone of geohash-int
https://github.com/bsm/geohashi

Last synced: 9 months ago
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Go(lang) clone of geohash-int

• Host: GitHub
• URL: https://github.com/bsm/geohashi
• Owner: bsm
• License: bsd-3-clause
• Created: 2015-11-23T09:17:25.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2017-06-28T15:50:49.000Z (almost 9 years ago)
• Last Synced: 2025-08-31T04:02:30.261Z (9 months ago)
• Language: Go
• Size: 21.5 KB
• Stars: 1
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# GeoHashi

[![Build Status](https://travis-ci.org/bsm/geohashi.png?branch=master)](https://travis-ci.org/bsm/geohashi)

[![GoDoc](https://godoc.org/github.com/bsm/geohashi?status.png)](http://godoc.org/github.com/bsm/geohashi)

[![Go Report Card](https://goreportcard.com/badge/github.com/bsm/geohashi)](https://goreportcard.com/report/github.com/bsm/geohashi)

[![License](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)

Geohash library for Go, optimised for performance. Inspired by [geohash-int](https://github.com/yinqiwen/geohash-int).

## Examples

Encode coordinates:

```go

func Encode() {

	lat, lon := 51.52463, -0.08411

	hash1 := geohashi.EncodeWithPrecision(lat, lon, 10)

	fmt.Printf("%d (%d)\n", hash1, hash1.Precision())

	hash2 := geohashi.EncodeWithPrecision(lat, lon, 20)

	fmt.Printf("%d (%d)\n", hash2, hash2.Precision())

}

```

Decode hash:

```go

func Decode() {

	hash := geohashi.Hash(90072520759854475)

	area := hash.Decode()

	lat, lon := area.Center()

	fmt.Printf("%.5f,%.5f\n", lat, lon)

	fmt.Println(area.Contains(51.52463, -0.08411))

}

```

## Precision

This library allows you to select the precision of the hash you want to create, up to a maximum of 26 bits.

The following table shows the maximum uncertainty (at the equator) for a given bit-precision:

|Bits| Uncertainty |

|----|-------------|

| 26 | ±0.35m      |

| 25 | ±0.65m      |

| 24 | ±1.3m       |

| 23 | ±2.6m       |

| 22 | ±5.3m       |

| 21 | ±11m        |

| 20 | ±21m        |

| 19 | ±42m        |

| 18 | ±84m        |

| 17 | ±170m       |

| 16 | ±340m       |

| 15 | ±680m       |

| 14 | ±1400m      |

| 13 | ±2700m      |

| 12 | ±5400m      |

| 11 | ±11000m     |

| 10 | ±22000m     |

| 9  | ±43000m     |

| 8  | ±86000m     |

| 7  | ±170000m    |

| 6  | ±350000m    |

| 5  | ±690000m    |

| 4  | ±1400000m   |

| 3  | ±2800000m   |

| 2  | ±5400000m   |

| 1  | ±10000000m  |