title: Am Chart does not load chart after ajax call
body: <p>I fetch data from API by making ajax call then pass this data to the chart. 
  I am not able to render the chart. Can anyone suggest me what may be the issue? </p>
  
  <p>This is my ajax call</p>
  
  <p>You can see after ajax call i am trying to push to scope variable and trying to add to chart.</p>
  
  <p>for reference please find in this link <a href="http://jsfiddle.net/w3vpc35o/41/" rel="nofollow noreferrer">http://jsfiddle.net/w3vpc35o/41/</a></p>
  
  <pre><code>  angular.module('amChartsDirectiveExample', ['amChartsDirective']).controller('amChartsController', function ($scope) {
  $scope.call = function(){
    $http({
              method: "get",
              global: false,
              async: true,
              url: "server/test.php
          }).
          success(function(data) {
        /*Assume data like like [{
          year: 2005,
          income: 23.5,
          expenses: 18.1
      }, {
          year: 2006,
          income: 26.2,
          expenses: 22.8
      }, {
          year: 2007,
          income: 30.1,
          expenses: 23.9
      }, {
          year: 2008,
          income: 29.5,
          expenses: 25.1
      }, {
          year: 2009,
          income: 24.6,
          expenses: 25
      }]*/
     $scope.rest = data
    $scope.amChartOptions = {
      data:$scope.res ,
      type: "serial",
      theme: 'black',
      categoryField: "year",
      rotate: true,
      pathToImages: 'https://cdnjs.cloudflare.com/ajax/libs/amcharts/3.13.0/images/',
      legend: {
          enabled: true
      },
      chartScrollbar: {
          enabled: true,
      },
      categoryAxis: {
          gridPosition: "start",
          parseDates: false
      },
      valueAxes: [{
          position: "top",
          title: "Million USD"
      }],
      graphs: [{
          type: "column",
          title: "Income",
          valueField: "income",
          fillAlphas: 1,
      }]
  }
    });
   }
  
  
  $scope.call();
  
    });
  </code></pre>