gistfile1.js

angular.module("testApp", [])
        .controller("testController", function ($scope) {
          $scope.base = 1;

          $scope.currency = "USD";

          $scope.multiplyByBase = function(amount) {
            var base = parseFloat($scope.base) ? $scope.base : 1;
            return amount * base;
          }

          $scope.changeCurrency = function(currency) {
            $scope.currency = currency;
            $scope.traders = traders[currency];
          }

          $scope.traders = traders[$scope.currency];

        });