V3: Radar Polar chart

HTML

<script src="http://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="http://www.amcharts.com/lib/3/radar.js"></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.gridType = "circles";
    valueAxis.fillAlpha = 0.05;
    valueAxis.fillColor = "#000000";
    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 = 225;
    guide.tickLength = 0;
    guide.toAngle = 315;
    guide.value = 0;
    guide.toValue = 14;
    guide.fillColor = "#0066CC";
    guide.fillAlpha = 0.6;
    valueAxis.addGuide(guide);
    
    // red fill
    guide = new AmCharts.Guide();
    guide.angle = 45;
    guide.tickLength = 0;
    guide.toAngle = 135;
    guide.value = 0;
    guide.toValue = 14;
    guide.fillColor = "#CC3333";
    guide.fillAlpha = 0.6;
    valueAxis.addGuide(guide);
    
    // WRITE                
    chart.write("chartdiv");
});