zend框架中的图表2

Question

I am working with zend framework 2 and i want to display charts in some views but it doesn't work!! This is my Action:

public function statvehAction(){
        $data = [
        'labels' => ["January","February","March","April","May","June","July"],
        'data' => [18,99,30,81,28,55,30]
        ];
        json_encode($data);
        $viewModel = new ViewModel(array('data' => $data));
        return $viewModel;
    }

this is my view:

<script src="../../../../jquery.min.js"></script>
<script src="../../../../chart.min.js"></script>
<script>
              (function($){
        var ctx = document.getElementById("chart").getContext("2d");


        $.ajax({
          type: "POST",
          url: "VehiculesController.php",
          dataType: "json"
        })
        .success(function(data) {
            var d = {
                labels: $data.labels,

                datasets : [
                    {
                        fillColor: "rgba(220,220,220,0.5)",
                        strokeColor: "rgba(220,220,220,1)",
                        data: data.data }] };

            var barChart = new Chart(ctx).Bar(d);


        });



    })(jQuery);

</script>

But when i want to diplay my chart i got a white page whith no error !! Please can you help me to solve this problem.