Radar chart API reference

Documentation about the Radar chart including information about all of the options that are available to you. The Radar chart can show multiple datasets and be filled or non-filled. It can show differences in the magnitude of the values in a given dataset.

• Example
• Properties
• Methods
• The coords and coords2 arrays
• Highlighting data series
• Events
• Effects

Example

<script>
    labels = ['John','Fred','Luis','Pete','Gary','Neil','Olga','Terry'];

    new RGraph.Radar({
        id: 'cvs',
        data: [
            [16,18,14,15,14,13,16,18],
            [16,15,14,16,18,16,15,14]
        ],
        options: {
            backgroundCircles: true,
            textSize: 16,
            labels: labels,
            colorsStroke: ['red', 'black'],
            colors: ['rgba(0,0,0,0)'],
            linewidth: 3,
            marginTop: 15,
            marginBottom: 15,
            marginLeft: 85,
            marginRight: 125,
            tooltips: '<b>%{property:labels[%{index}]}\'s results:</b>%{key}',
            tooltipsFormattedKeyLabels: ['2001','2002'],
            tooltipsFormattedKeyColors: ['red', 'black'],
            tooltipsFormattedUnitsPost: '%',
            tooltipsCss: {
                fontSize: '16pt',
                boxShadow: '',
                textAlign: 'left'
            }
        }
    }).draw();
</script>

Properties

You can use these properties to control how the chart appears. You can set them by including them in the options section of the configuration as is shown above.

• Chart configuration properties
• Background properties
• Margin properties
• Color properties
• Fill properties
• Title properties
• Labels and text properties
• Scale properties
• Axis properties
• Key properties
• Interactive features properties
• Miscellaneous properties

Chart configuration properties

Background properties

Margin properties

Color properties

Fill properties

Title properties

Labels and text properties

<div style="margin-left: 50px; display: inline-block">
    <canvas id="cvs" width="650" height="250"></canvas>
</div>

<div style="margin-left: 50px; display: inline-block">
    <canvas id="cvs" width="650" height="250"></canvas>
</div>

Scale properties

Axis properties

Key properties

Interactive features properties

tooltipsFormattedKeyColorsCss : {
    border: "1px solid #ddd";
}

tooltipsFormattedListItems: [
    ['Bill','Jerry','Berty'], // First tooltip
    ['Gill','Carrie','Lucy'], // Second tooltip
    ['Pob','Nobby','Hilda']   // Third tooltip
]

.RGraph_tooltip ul#rgraph_formatted_tooltips_list li {
    text-align: left;
    color: yellow;
}

tooltips: {
    borderLeft: 'gray 2px solid',
    borderBottom: 'gray 2px solid'
}

tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt'
}

tooltipsFormattedKeyColorsCss : {
    border: "1px solid #ddd";
}

tooltipsFormattedListItems: [
    ['Bill','Jerry','Berty'], // First tooltip
    ['Gill','Carrie','Lucy'], // Second tooltip
    ['Pob','Nobby','Hilda']   // Third tooltip
]

.RGraph_tooltip ul#rgraph_formatted_tooltips_list li {
    text-align: left;
    color: yellow;
}

tooltips: {
    borderLeft: 'gray 2px solid',
    borderBottom: 'gray 2px solid'
}

tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt'
}

Miscellaneous properties

Methods

An accessor that you can use to retrieve the values of properties.

An accessor that you can use to set the values of properties.

<script>
    radar.canvas.onclick = function (e)
    {
        RGraph.redraw();
    
        var canvas  = e.target,
            obj     = canvas.__object__,
            shape   = obj.getShape(e);

        if (shape) {
            
            var x = shape.x,
                y = shape.y;

            obj.path(
                'b a % % 5 0 6.29 false s black f red',
                x, y
            );
        }
    }
</script>

This function returns the distance from the center for a particular value - the radius of an imaginary circle in effect.

The Radar chart values are spaced equally around the chart (in terms of their angles). So the angle for a particular data point can easily be calculated. This method makes it even easier. Simply pass it the total number of data points that you have and the zero-indexed number of the one you want and this will return you an appropriate angle. eg for the fourth item out of 8 total data points you would do this: obj.getAngle(8, 3);

This method can be used to set an event listener on an object. It operates in a similar way to the jQuery on() function. The first argument is the event that you wish to attach to and the second is the handler function. For example:

obj.on('draw', function (obj)
{
    // Put your event code here
});

The function is useful if you use method chaining when creating your charts:

new RGraph.Radar({
    id: 'cvs',
    data: [8,6,4,3,8,7,4,9],
    options: {
    }
}).on('draw', function (obj)
{
    // Put your draw event code here

}).on('click', function (e, shape)
{
    // Put your click event code here
}).draw()

The exec function is documented here.

The responsive() function helps your charts respond to different browser window sizes and screen resolutions. For example for smaller screens you might want to have angled labels or show shorter versions of them completely.

The responsive() function is documented on its own page here.

If you're using the fillClick or the fillMousemove options then you may want to make use of this function - which will highlight a dataset for you. You pass it the index of the dataset (0 for the first dataset, 1 for the second etc) and this will add highlighting for you. It uses the highlightFill and highlightStroke options for the colors.

The coords and coords2 arrays

The X/Y coordinates for the points on the Radar chart are held in two different ways. The obj.coords array is one long array containing all of the coordinates for all of the datasets. The obj.coords2 on the other hand holds the same coordinates but in a multi-dimensional way - so, keeping in mind that the numbering starts at zero, obj.coords2[1][3] refers to the fourth point in the second dataset.

Highlighting data series

New in November 2012 is the ability to highlight a data series. This allows you to associate a function to run when a data series is clicked or hovered over. In addition to being able to run a function you can also specify a set of tooltips which are shown when the datasets are clicked on or hovered over. These tooltips can be shown using the mousemove or the click events. If you need it - there is a obj.HighlightDataset(dataset) method which you can use to highlight a specific dataset. The appropriate properties and their default values are:

• fillClick (null - should be a function)
• fillMousemove (null - should be a function)
• fillTooltips (null - should be an array of strings)
• fillClickHighlight (false)
• fillMousemoveHighlight (false)
• fillHighlightFill (rgba(255,255,255,0.7))
• fillHighlightStroke (rgba(0,0,0,0))
• fillMousemoveRedraw (false)

<script>
    new RGraph.Radar({
        id: 'cvs',
        data: [
            [4,8,6,5,3,5,4,6,8,7],
            [4,2,3,5,1,6,5,4,5,3]
        ],
        options: {
            marginBottom: 35,
            labels: ['Bob','Richard','Luis','Pete','Gemma','Karen','Lee','Olga','Kevin','Luis'],
            colors: ['red', 'green'],
            colorsAlpha: 0.4,
            axesColor: 'rgba(0,0,0,0)',
            accumulative: true,
            backgroundCirclesPoly: true,
            colorsStroke: 'rgba(0,0,0,0)',
            textSize: 10,
            fillTooltips: ['The first datasets tooltip', 'The second datasets tooltip'])
        }
    }).draw();
</script>

Events

RGraph supports custom events that allow you to easily add interactivity to your charts if required. The following events are available:

• annotatebegin This event fires at the start of annotating - like the standard mousedown event.
• annotate This event fires (repeatedly) during annotating - like the standard mousemove event.
• annotateend This event fires at the end of annotating - like the standard mouseup event.
• annotateclear This event fires at the end of the RGraph.clearAnnotations() function.
• beforeclear This event fires at the start of the RGraph.clear() function.
• clear This event fires at the end of the RGraph.clear() function.
• click This is similar to the standard canvas click event but this only fires when you click on a bar - not the whole canvas.
• beforecontextmenu This event fires when you have the contextmenu enabled and it is about to appear.
• contextmenu This event fires when you have the contextmenu enabled and it has been displayed.
• beforedraw This event fires at the start of the draw() method before anything has been done.
• firstdraw This event fires at the end of the draw() function - but only the first time that the draw() function is called.
• draw This event fires at the end of the draw() function.
• beforeinteractivekey When you're using the interactive key this event fires just before the key and chart are highlighted.
• afterinteractivekey When you're using the interactive key this event fires just after the key and chart are highlighted.
• keyclick This event fires when you click on the key - you don't have to be using the interactive key however.
• mousemove This event is similar to the standard mousemove event but only fires when you move the mouse over a bar on the chart.
• mouseover This event is similar to the standard mouseover event but only fires when you move the mouse over a bar on the chart.
• mouseout This event is similar to the standard mouseout event but only fires when you move the mouse away from a bar on the chart that you've previously hovered over.
• beforetooltip This event fires at the start of the tooltip showing process.
• tooltip This event fires after a tooltip has been shown.

new RGraph.Radar({
    id: 'cvs',
    data: [4,8,6,3,5,8,9],
    options: {
    }
}).on('draw', function (obj)
{
    console.log('The draw event has fired');
    
}).draw();

Effects

• The grow effect (effects-radar-grow.html in the download archive)
• The trace effect (effects-radar-trace.html in the download archive)

<script>
    // Optional callback function that's called when the effect is complete
    function myCallback (obj)
    {
        // ...
    }

    new RGraph.Radar({
        id: 'cvs',
        data: [8,7,6,8,4,9,5,9,8],
        options: {
            marginLeft: 35
        }
    }).trace({frames: 60}, myCallback)
    // .grow({frames: 60}, myCallback)
</script>