Finleap
We have some customer records in a text file (customers.json) -- one customer per line, JSON-encoded. We want to invite any customer within 100km of our Berlin office for some food and drinks. Write a program that will read the full list of customers and output the names and user ids of matching customers (within 100km), sorted by User ID (ascending).
You can use the first formula from this Wikipedia article to calculate distance. Don't forget, you'll need to convert degrees to radians.
The GPS coordinates for our Berlin office are 52.508283, 13.329657
Installation
Add this line to your application's Gemfile:
gem 'finleap'And then execute:
$ bundle install
Or install it yourself as:
$ gem install finleap
Usage
After installing the gem you can try it by
irb
require 'finleap'
Finleap::Customers::Geo.in_range(50)
=> [{"user_id"=>6, "name"=>"Nolan Little", "latitude"=>52.16209823311126, "longitude"=>13.543372863802071}]
you can change the range also and the result will be array of sorted by user_id hashes
> Finleap::Customers::Geo.in_range(100)
=> [{"user_id"=>4, "name"=>"Ernesto Breitenberg", "latitude"=>52.94260786195436, "longitude"=>13.067312769068188},
{"user_id"=>6, "name"=>"Nolan Little", "latitude"=>52.16209823311126, "longitude"=>13.543372863802071},
{"user_id"=>14, "name"=>"Burt Klein Esq.", "latitude"=>53.1265734799671, "longitude"=>12.699384236532275},
{"user_id"=>19, "name"=>"Eldridge Funk DDS", "latitude"=>52.147558277671415, "longitude"=>13.804602080070971},
{"user_id"=>25, "name"=>"Maggie Trantow", "latitude"=>53.10974927389135, "longitude"=>13.013782063005134},
{"user_id"=>29, "name"=>"Arden Kshlerin", "latitude"=>52.61428145536312, "longitude"=>14.246534306873425},
{"user_id"=>30, "name"=>"Candi Larkin", "latitude"=>51.7136432343531, "longitude"=>13.53599402401951},
{"user_id"=>35, "name"=>"Blondell Hermiston", "latitude"=>52.62033397021099, "longitude"=>14.716070229258861},
{"user_id"=>36, "name"=>"Kemberly Durgan DC", "latitude"=>52.07953938789886, "longitude"=>14.480735257348044},
{"user_id"=>40, "name"=>"Rafael Streich IV", "latitude"=>52.531792624998715, "longitude"=>12.177849950380875},
{"user_id"=>42, "name"=>"Raymundo Schuster", "latitude"=>52.677794195484154, "longitude"=>12.539436329812464},
{"user_id"=>49, "name"=>"Cole Predovic JD", "latitude"=>52.817435894229774, "longitude"=>14.280626271845067}]
By using this gem we can get the list of customers ids and names so we can then send the invitation to them.
specs
Development
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/finleap.
License
The gem is available as open source under the terms of the MIT License.