# Geocalc
[](https://travis-ci.org/yltsrc/geocalc)
[](https://hex.pm/packages/geocalc)
Documentation: [http://hexdocs.pm/geocalc](http://hexdocs.pm/geocalc)
Calculate distance, bearing and more between latitude/longitude points
All the formulas are adapted from
[http://www.movable-type.co.uk/scripts/latlong.html](http://www.movable-type.co.uk/scripts/latlong.html)
## Installation
First, add Geocalc to your `mix.exs` dependencies:
```elixir
def deps do
[{:geocalc, "~> 0.5"}]
end
```
Then, update your dependencies:
```sh-session
$ mix deps.get
```
Now, list the `:geocalc` application as your
application dependency:
```elixir
def application do
[applications: [:geocalc]]
end
```
## Usage
### Calculate distance (in meters) between 2 points
```elixir
Geocalc.distance_between([50.0663889, -5.7147222], [58.6438889, -3.07])
# => 968853.5464535094
```
### Get destination point given distance (meters) from start and end point
```elixir
Geocalc.destination_point([50.0663889, -5.7147222], [58.6438889, -3.07], 100_000)
# => {:ok, [50.95412546615634, -5.488452905258299]}
```
### Get destination point given distance (meters) and bearing from start point
```elixir
Geocalc.destination_point([50.0663889, -5.7147222], 2.123, 100_000)
# => {:ok, [49.58859917965055, -4.533613856982982]}
```
### Calculate bearing from start and end points
```elixir
Geocalc.bearing([50.0663889, -5.7147222], [58.6438889, -3.07])
# => 0.1591708517503001
```
### Get intersection point given start points and bearings
```elixir
Geocalc.intersection_point([50.0663889, -5.7147222], 2.123, [55.0663889, -15.7147222], 2.123)
# => {:ok, [48.04228582473962, -1.0347033632388496]}
Geocalc.intersection_point([50.0663889, -5.7147222], 2.123, [50.0663889, -5.7147222], 2.123)
# => {:error, "No intersection point found"}
```
### Get bounding box from a point and radius
```elixir
berlin = [52.5075419, 13.4251364]
radius = 10_000
Geocalc.bounding_box(berlin, radius)
# => [[52.417520954378574, 13.277235453275123], [52.59756284562143, 13.573037346724874]]
```
### Get geographical center point
```elixir
berlin = [52.5075419, 13.4251364]
london = [51.5286416, -0.1015987]
rome = [41.9102415, 12.3959161]
Geocalc.geographic_center([berlin, london, rome])
# => [48.810406537400254, 8.785092188535195]
```
### Convert degrees to radians
```elixir
Geocalc.degrees_to_radians(245)
# => -2.007128639793479
```
### Convert radians to degrees
```elixir
Geocalc.radians_to_degrees(1.234)
# => 70.70299191914359
```
## Geocalc.Point protocol
Everything which implements `Geocalc.Point` protocol can be passed as a point
argument for any function in this library.
We already have implementations for `List`, `Tuple` and `Map`.
You can define your own implementations if you need, everything we need to know
to do calculations are `latitude` and `longitude`.
