haversine

README

Haversine

Package haversine provides the great circle distance between two points on the surface of the earth. Points are identified by latitude and longitude, and distance results can be returned in nautical miles, statute miles, or kilometers.

The curvature of the earth dictates that the shortest distance between two points cannot be a straight line between the points. The Haversine formula provides an approximation for the shortest great circle route over the surface of earth that connects the two points. In this figure the dotted yellow line is the arc of a great circle. Image courtesy USGS.

Installation

go get github.com/FATHOM5/haversine

Usage

The example below shows how far I'd have to walk in my boots to go visit my co-founder.

package main

import (
    "fmt"

    "github.com/FATHOM5/haversine"
)

func main() {
    austin := haversine.Coord{ // Austin, Texas
        Lat: 30.2672,
        Lon: -97.7431,
    }
    paloAlto := haversine.Coord{ // Palo Alto, California
        Lat: 37.4419,
        Lon: -122.1430,
    }

    nm := haversine.Distance(austin, paloAlto)

    fmt.Printf("%.1f miles is a long walk to Silicon Valley.\n", nm)

// Output: 1286.1 miles is a long walk to Silicon Valley.
}

Documenation

• http://godoc.org/github.com/FATHOM5/haversine

References

• https://plus.maths.org/content/lost-lovely-haversine
• https://en.wikipedia.org/wiki/Haversine_formula
• Many thanks to the original author, umahmood, for a great package to begin this fork.

License

See LICENSE for rights and limitations (MIT).

Documentation

Overview

Package haversine provides the great circle distance between two points on the surface of the earth. Points are identified by latitude and longitude, and distance results are returned in nautical miles. Functions are also provided to return the distance in kilometers or statute miles.

The below example shows how to calculate the shortest path between two coordinates on the surface of the Earth.

package main

import (
    "fmt"

    "github.com/FATHOM5/haversine"
)

func main() {
    austin := haversine.Coord{ // Austin, Texas
        Lat: 30.2672,
        Lon: -97.7431,
    }
    paloAlto := haversine.Coord{ // Palo Alto, California
        Lat: 37.4419,
        Lon: 122.1430,
    }

    nm := haversine.Distance(austin, paloAlto)

    fmt.Printf("%.1f miles is a long walk to Silicon Valley.\n", nm)
}

Index

• func Distance(p, q Coord) (nm float64)
• func DistanceKm(p, q Coord) (km float64)
• func DistanceMi(p, q Coord) (mi float64)
• type Coord

Examples

• Distance

Functions

func Distance

func Distance(p, q Coord) (nm float64)

Distance calculates the shortest path between two coordinates on the surface of the Earth and returns the result in nautical miles.

Example

package main

import (
	"fmt"

	"github.com/FATHOM5/haversine"
)

func main() {
	austin := haversine.Coord{ // Austin, Texas
		Lat: 30.2672,
		Lon: -97.7431,
	}
	paloAlto := haversine.Coord{ // Palo Alto, California
		Lat: 37.4419,
		Lon: -122.1430,
	}

	nm := haversine.Distance(austin, paloAlto)

	fmt.Printf("%.1f miles is a long walk to Silicon Valley.\n", nm)

}

Output:
1286.1 miles is a long walk to Silicon Valley.

func DistanceKm

func DistanceKm(p, q Coord) (km float64)

DistanceKm calculates the shortest path between two coordinates on the surface of the Earth and returns the result in kilometers.

func DistanceMi

func DistanceMi(p, q Coord) (mi float64)

DistanceMi calculates the shortest path between two coordinates on the surface of the Earth and returns the result in statute miles.

Types

type Coord

type Coord struct {
	Lat float64
	Lon float64
}

Coord represents a geographic coordinate.