如何使Amcharts动画数据工作?

var chart = AmCharts.makeChart("chartdiv", {
	"type": "serial",
	"theme": "light",
	"dataProvider": generateChartData(),
	"graphs": [{
		"valueField": "value",
		"type": "column",
    "fillAlphas": 1,
		"alphaField": "alpha1"
	}, {
		"valueField": "value2",
    "fillAlphas": 1,
		"type": "column",
		"alphaField": "alpha2"
	}],
	"valueAxes": [{
		"minimum": 0,
		"maximum": 400
	}],
	"chartCursor": {},
	"categoryAxis": {
		"parseDates": true,
		"minPeriod": "mm"
	},
	"zoomOutOnDataUpdate": false,
	"categoryField": "date"
});


function generateChartData() {
	var chartData = [];
	var firstDate = new Date( 2012, 0, 1 );
	firstDate.setDate( firstDate.getDate() - 1000 );
	firstDate.setHours( 0, Math.floor(Math.random() * 10), 0, 0 );

	for ( var i = 0; i < 10; i++ ) {
		var newDate = new Date( firstDate );
		newDate.setHours( 0, i, 0, 0 );

		var a = Math.round( Math.random() * ( 200 + i ) ) + 100 + i;
		var b = Math.round( Math.random() * ( 200 + i ) ) + 100 + i;

    chartData.push( {
      date: newDate,
      value: a,
      value2: b,
      alpha1: (Math.random() < 0.5 ? 0 : 1),
      alpha2: (Math.random() < 0.5 ? 0 : 1)
    } );
	}

	return chartData;
}


function loop() {
	var data = generateChartData();

	chart.animateData(data, {
		duration: 1000,
		complete: function () {
			setTimeout(loop, 2000);
		}
	});
}

chart.addListener("init", function () {
	setTimeout(loop, 1000);
});

html, body {
  width: 100%;
  height: 100%;
  margin: 0px;
}

#chartdiv {
	width: 100%;
	height: 100%;
}

<script src="https://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="https://www.amcharts.com/lib/3/serial.js"></script>
<script src="https://www.amcharts.com/lib/3/themes/light.js"></script>
<script src="https://www.amcharts.com/lib/3/plugins/animate/animate.min.js"></script>

<div id="chartdiv"></div>