Creating Chart from List in SharePoint 2013 with Chart.js Not working?

I want to create chart from List in SharePoint 2013 with:

http://www.chartjs.org/

and followed : https://www.simego.com/Blog/2013/09/Charts-and-Office-365-SharePoint-Online

blog but it is not working

my code is:

<script type="text/javascript"  src="/sites/testdev/SiteAssets/Chart.js" ></script>     
<script type="text/javascript">
    var collListItem; //ListItems
var chartX = [];  //X-Axis Labels
var chartY = [];  //Y-Axis Values

var chartJs = "/sites/testdev/SiteAssets/Chart.js";
var listName = "TestC"; //Data List Name
var xAxisName = "Title";    //X-Axis Label Names from List
var yAxisName = "Values";    //Y-Axis Values from List
var chartId = "myChart";    //Chart Canvas Div

SP.SOD.executeOrDelayUntilScriptLoaded(function() {

var clientContext = new SP.ClientContext.get_current();
var oList = clientContext.get_web().get_lists().getByTitle(listName);

var camlQuery = new SP.CamlQuery();
camlQuery.set_viewXml('<View></View>');
this.collListItem = oList.getItems(camlQuery);
clientContext.load(collListItem);
clientContext.executeQueryAsync(function() {
var listItemEnumerator = collListItem.getEnumerator();

    //Create Points from ListData
    while (listItemEnumerator.moveNext()) {
        var oListItem = listItemEnumerator.get_current();
        chartX.push(oListItem.get_item(xAxisName));
        chartY.push(oListItem.get_item(yAxisName));
    }

    //Load Chart JS
    loadJS(chartJs, function() {
        //Generate Data
        var data = {
            labels: this.chartX,
            datasets: [
                {
                    data: this.chartY
                }
            ]
        };

        //Display Chart
        var ctx = document.getElementById(chartId).getContext("2d");
        var myNewChart = new Chart(ctx).Bar(data);
      });

    }, null);

 }, 'SP.js');

 function loadJS(src, callback) {
  var s = document.createElement('script');
  s.src = src;
  s.async = true;
  s.onreadystatechange = s.onload = function() {
    var state = s.readyState;
    if (!callback.done && (!state || /loaded|complete/.test(state))) {
        callback.done = true;
        callback();
    }
  };
 document.getElementsByTagName('head')[0].appendChild(s);
 }
</script>