RADAR SERIES or Spider web chart:

RADAR SERIES or Spider web chart:
A data series to be rendered as the area inside a series of connected points in a radial Visualforce chart. Radar charts are also sometimes called "spider web" charts. At a minimum you must specify the fields in the data collection to use as X and Y values for each point, as well as a radial axis to scale agains

public class crChartController {

    // Return a list of data points for a chart 

    

    public List<Data> getData() {

        return crChartController.getChartData();

    }

    

    // Make the chart data available via JavaScript remoting 

    

    @RemoteAction

    public static List<Data> getRemoteData() {

        return crChartController.getChartData();

    }

    // The actual chart data; needs to be static to be 

    

    // called by a @RemoteAction method 

    

    public static List<Data> getChartData() {

        List<Data> data = new List<Data>();

        data.add(new Data('Jan', 30, 90, 55));

        data.add(new Data('Feb', 44, 15, 65));

        data.add(new Data('Mar', 25, 32, 75));

        data.add(new Data('Apr', 74, 28, 85));

        data.add(new Data('May', 65, 51, 95));

        data.add(new Data('Jun', 33, 45, 99));

        data.add(new Data('Jul', 92, 82, 30));

        data.add(new Data('Aug', 87, 73, 45));

        data.add(new Data('Sep', 34, 65, 55));

        data.add(new Data('Oct', 78, 66, 56));

        data.add(new Data('Nov', 80, 67, 53));

        data.add(new Data('Dec', 17, 70, 70));

        return data;

    }

    

    // Wrapper class 

    

    public class Data {

        public String name { get; set; }

        public Integer data1 { get; set; }

        public Integer data2 { get; set; }

        public Integer data3 { get; set; }

        public Data(String name, Integer data1, Integer data2, Integer data3) {

            this.name = name;

            this.data1 = data1;

            this.data2 = data2;

            this.data3 = data3;

        }

    }

}

<apex:page controller="crChartController" >
 <apex:chart height="530" width="700" legend="true" data="{!data}">
    <apex:legend position="left"/>
    <apex:axis type="Radial" position="radial">
        <apex:chartLabel />
    </apex:axis>
    <apex:radarSeries xField="name" yField="data1" tips="true" opacity="0.4"/>
    <apex:radarSeries xField="name" yField="data2" tips="true" opacity="0.4"/>
    <apex:radarSeries xField="name" yField="data3" tips="true" 
        markerType="cross" strokeWidth="2" strokeColor="#f33" opacity="0.4"/>
</apex:chart>

</apex:page>