Random coordinates for Google Maps with Typescript

What's for?

I'm developing a small Mobile Application using Ionic and Angular. The app uses a Map to show to the user some nearby services.

For the test phase, as you can imagine, we don't have real service to show and the user/demo can be anywhere.

To help with the test I created a simple generator of GPS coordinates based on the location of the user.

Here the package NPM and the code source GitHub

The coordinates of the 3 cook's hats are generated from the library. The green point is the current position.

You can test the app yourself (alpha on google play store):

https://play.google.com/apps/testing/com.wicooks.next

How to use it

The library is still a work in progress but already working.

You simply need the starting coordinates (latitude/longitude) and pass the maximum number of kilometers of distance for the new coordinates.

The coordinates are created using this function:

import {LatLng as LatitudeLongitude} from "@molteni/coordinate-utils/dist/LatLng"; 
 
 generateCoordinates() : LatitudeLongitude { 
    return RandomCoordinateUtils.randomCoordinateFromPositionWithExplicitLatLng(this.currentLocation.lat, this.currentLocation.lng, 0.1); 
  }; 

To the current location are added/subtracted 0 to 100 meters to the longitude and latitude.

How it works

The calculation is not extremely accurate but is enough for the Use Cases of most developers.

 
const EARTH_RADIUS = 6378; 
 
    export function addKMToLatitude(latitude : number, kilometers : number) : number { 
        return latitude + (kilometers / EARTH_RADIUS) * (180 / Math.PI); 
    } 
 
    export function addKMToLongitude(latitude : number, longitude : number, kilometers : number) : number { 
        return longitude + (kilometers / EARTH_RADIUS) * (180 / Math.PI) / Math.cos(latitude * Math.PI / 180); 
    } 
 
    export function  getKMperDegree() { 
        return (2*Math.PI / 360) * EARTH_RADIUS; 
    } 
}