geographic-math/README.md

A set of useful geo functions

# Geo Math

## Install
```sh
$ npm install geographic-math
```

## Functions

* `isIncluded(position, polygon)` returns `true` if the target position is inside the polygon defined by an array of `{ lat, lon }`
* `getDistance(position1, position2)` returns distance in km between the positions

## Usage
```javascript
import { getDistance, isIncluded } from 'geographic-math';

const polygon = [
  {"lat": 55.705429470455414, "lon": 37.621419873046754},
  {"lat": 55.70077659231783, "lon": 37.6090602539062},
  {"lat": 55.70930644415837, "lon": 37.5836543701171},
  {"lat": 55.72015991493216, "lon": 37.554128613281215},
  {"lat": 55.741470416597515, "lon": 37.53421589355463},
  {"lat": 55.76509203888301, "lon": 37.53833576660153},
  {"lat": 55.774768881457526, "lon": 37.55412861328109},
  {"lat": 55.79179426544748, "lon": 37.57404133300736},
  {"lat": 55.79372849670679, "lon": 37.65163227539058},
  {"lat": 55.779412909511215, "lon": 37.67017170410151},
  {"lat": 55.77747796540244, "lon": 37.679784741210824},
  {"lat": 55.76702760045296, "lon": 37.69214436035153},
  {"lat": 55.74611842820403, "lon": 37.70038410644526},
  {"lat": 55.71977234312517, "lon": 37.7072505615234},
  {"lat": 55.709306444108734, "lon": 37.66673847656241},
  {"lat": 55.70349083865831, "lon": 37.65506550292964}
];

isInside({"lat":55.72907299961868,"lon":37.614210095214084}, polygon); // true
isInside({"lat":55.79198769178762,"lon":37.677038159178}, polygon); // false
getDistance({"lat":55.79198769178762,"lon":37.677038159178}, {"lat":55.72907299961868,"lon":37.614210095214084}); // 8
```