app/assets/javascripts/epgp.js.coffee
calculate_epgp = ->
ep = parseInt($('#epgp-ep-input').val())
gp = parseInt($('#epgp-gp-input').val())
pr = ep / (gp + 100)
$('#epgp-pr-output').val(pr)
$(document).on 'ready page:load', ->
$('#epgp-ep-input').on 'input', (e) ->
calculate_epgp()
$('#epgp-gp-input').on 'input', (e) ->
calculate_epgp()