Nearest Customer

Solution to get customers whose GPS coordinates are in specified km radius.

Installation

npm i nearest_customer

Usage

var nearestCustomer = require('nearest_customer');
var nearestCustomerList = nearestCustomer(53.339428, -6.257664, 100);

Output

Solution will return list of customers available in mentioned range. List will also be sorted on user_id of customer in ascending order.

Detail Explanation

Three parameters are required where first parameter is Latitude of source point, second parameter is Longitude of source point & third parameter is range in km, under which customers whose GPS coordinates are present will come. Inside data/customers_data.txt, customers record are present as one customer per line in JSON format. For every customer, distance is calculated between his/her coordinates & source coordinated provided by user.

For calculating distance, Haversine Formula is used.

Please refer about Haversine Formula on Wikipedia page. Haversine formula (https://en.wikipedia.org/wiki/Haversine_formula)

Assumptions

In this solution, Earth is assumed as a sphere. Haversine formula determines distance between 2 points on sphere. As our Earth it spheroid and not a perfect sphere, an error of around 0.3% is present.