grid aggregates

HTML

<script src="http://cdn.kendostatic.com/2012.1.322/js/kendo.all.min.js"></script>
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.322/styles/kendo.common.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.322/styles/kendo.metro.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.322/styles/kendo.dataviz.min.css">
<div id="chart"></div>

JavaScript

var data = [{
    "OS": "Windows",
    "TotalUsers": 4},
{
    "OS": "IPhone",
    "TotalUsers": 3},
{
    "OS": "Android",
    "TotalUsers": 1},
{
    "OS": "Windows",
    "TotalUsers": 2},
{
    "OS": "IPhone",
    "TotalUsers": 6},
{
    "OS": "Android",
    "TotalUsers": 5},
{
    "OS": "Windows",
    "TotalUsers": 2},
{
    "OS": "IPhone",
    "TotalUsers": 3},
{
    "OS": "Android",
    "TotalUsers": 7},
                                 ];

var dataSource = new kendo.data.DataSource({
    data: data,
    group: {
        field: "OS"
    }
});

$("#chart").kendoChart({
    theme: $(document).data("kendoSkin") || "default",
    seriesDefaults: {
        type: "column"
    },
    tooltip: {
        visible: true
    },
    dataSource: dataSource,
    series: [{
        field: "TotalUsers"}],
    categoryAxis: {
        categories: ["Pakistan", "United States", "India"],
        labels: {
            rotation: 45
        }
    }
});