amcharts Radar polar

HTML

<script src="http://www.amcharts.com/lib/amcharts.js" type="text/javascript"></script>
<div id="chartdiv" style="width: 100%; height: 362px;"></div>

JavaScript

var chart;

var chartData = [{
    direction: "N",
    value: 8},
{
    direction: "NE",
    value: 9},
{
    direction: "E",
    value: 4.5},
{
    direction: "SE",
    value: 3.5},
{
    direction: "S",
    value: 9.2},
{
    direction: "SW",
    value: 8.4},
{
    direction: "W",
    value: 11.1},
{
    direction: "NW",
    value: 10}];


AmCharts.ready(function() {
    // RADAR CHART
    chart = new AmCharts.AmRadarChart();
    chart.dataProvider = chartData;
    chart.categoryField = "direction";
    chart.startDuration = 1;

    // TITLE
    chart.addTitle("Prevailing winds", 15);

    // VALUE AXIS
    var valueAxis = new AmCharts.ValueAxis();   
    valueAxis.fillColor = "red";
    valueAxis.axisAlpha = 0.2;
    valueAxis.gridAlpha = 0;
    valueAxis.fontWeight = "bold";
    valueAxis.minimum = 0;
    chart.addValueAxis(valueAxis);

    // GRAPH
    var graph = new AmCharts.AmGraph();
    graph.lineColor = "#FFCC00";
    graph.fillAlphas = 0.4;
    graph.bullet = "round";
    graph.valueField = "value";
    graph.balloonText = "[[category]]: [[value]] m/s";
    chart.addGraph(graph);

    // GUIDES
    // blue fill
    var guide = new AmCharts.Guide();
    guide.angle = 125;
    guide.tickLength = 0;
    guide.toAngle = 35;
    guide.value = 0;
    guide.toValue = 124;
    guide.fillColor = "#0066CC";
    guide.fillAlpha = 0.6;
    valueAxis.addGuide(guide);

    // red fill
    guide = new AmCharts.Guide();
    guide.angle = 145;
    guide.tickLength = 0;
    guide.toAngle = 155;
    guide.value = 0;
    guide.toValue = 14;
    guide.fillColor = "#CC3333";
    guide.fillAlpha = 0.6;
    valueAxis.addGuide(guide);

    // WRITE                
    chart.write("chartdiv");
});