How to add additional form fields using angularjs?

I have researched online on how to create an additional form field. The method I am using comes from this site.

http://mrngoitall.net/blog/2013/10/02/adding-form-fields-dynamically-in-angularjs/

So basically what I am trying to do, is have data inputted in. But I don't know how many data points a certain person would like to put in. So I what to enable it so I can let them put additional points if they wish.

I have this in my tag:

  <script>
  function AngularCtrl($scope) {
  function Controller($scope) {
    $scope.master = {};

    $scope.update = function(user) {
      $scope.master = angular.copy(user);
    };

    $scope.reset = function() {
      $scope.user = angular.copy($scope.master);
    };

    $scope.reset();
  }

$scope.choices = [{id: 'choice1'}]; 

$scope.addNewChoice = function() {
    var newItemNo = $scope.choices.length+1;
    $scope.choices.push({'id':'choice'+newItemNo});
};


$scope.showAddChoice = function(choice) {
    return choice.id === $scope.choices[$scope.choices.length-1].id;
};



$scope.showChoiceLabel = function (choice) {
    return choice.id === $scope.choices[0].id;
}



}
</script>

I then have this in my tag:

<div class="form-group" ng-controller="Controller" data-ng-repeat="choice in choices">
  <form novalidate class="simple-form">
        Title of Chart: <input type="text" ng-model="chart.title" /><br />
        Series Name: <input type="text" ng-model="chart.series" /><br />
        Series Data: <input type="text" ng-model="series.data" /><br>

        <label for="choice" ng-show="showChoiceLabel(choice)">Choices</label>
        <button ng-show="showAddChoice(choice)" ng-
         click="addNewChoice()">Add another choice</button>
        <input type="text" ng-model="choice.name" name="" placeholder="Enter
         a new data point">         
        <br>
        <button ng-click="reset()">RESET</button>
        <button ng-click="update(user)">SAVE</button>
  </form>
</div>

So as you can see, what I have is 4 form fields. I want choices to add a new form field. I have the button, but when I click the button to add another form field; it does not work. It stays the same.

I was wondering if what I have in my tags was off a bit.

Thank you for the help. Been struggling on this for hours.