Pie chart API reference

Summary: Documentation about the Pie chart including information about all of the options that are available to you. The Pie chart can show a single dataset and with the donut option it can show multiple datasets. Some people find them to be quite contentious though as comparing individual pieces of data can be tricky.

• Example
• Properties
• Methods
• Custom RGraph events that are available
• The Horseshoe meter
• The Segmented meter
• The Activity meter
• Animation effects

Example

<script>
    labels = ['Fred','Rich','John','Paul','Jason','Hoolio','Kevin'];

    new RGraph.Pie({
        id: 'cvs',
        data: [564,155,499,611,322,568,389],
        options: {
            tooltips: '<b>Results:</b><br />%{key}',
            tooltipsFormattedKeyLabels: labels,
            labels: labels,
            linewidth: 2,
            colorsStroke: 'white',
            shadow: false,
            tooltipsCss: {
                fontSize: '16pt',
                textAlign: 'left'
            },
            exploded: [25]
        }
    }).draw();
</script>

Properties

You can use these properties to control how the pie chart looks. You can set them by using the set() method. Eg:

obj.set('name', 'value');

• Chart configuration properties
• Margin properties
• Color properties
• Labels and text properties
• Title properties
• Shadow properties
• Interactive features properties
• Key properties
• Miscellaneous properties

Chart configuration properties

Margin properties

Color 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>

Title properties

Shadow 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'
}

Key properties

Miscellaneous properties

Methods

<script>
    pie.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,
                radius = shape.radius,
                start  = shape.angleStart,
                end    = shape.angleEnd;

            obj.path(
                'b m % % a % % % % % false c s black f red',
                x, y, x, y, radius, start, end
            );
        }
    }
</script>

The explode() function allows you to programmatically trigger the exploding (ie the highlighting of) a particular segment. The explode() method is used like so:

<script>
    pie = new RGraph.Pie({
        id: 'cvs',
        data: [8,9,4,6]
    }).draw();

    pie.explode(index, size);
</script>

The index argument is the zero-indexed segment to operate on (counting from the north axis). And the size is measured in pixels.

This method can be used to get an appropriate angle for a value using the "scale" of the Pie chart. So if your Pie chart is showing values that go from 0-100 and your requested value is 50, this method will return an angle for the bottom of the Pie chart (ie half way around).

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:

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

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

new RGraph.Pie({
    id: 'cvs',
    data: [4,5,3,8,6,3]
}).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.

Custom RGraph events that are available

Custom RGraph events are events that RGraph fires when certain actions occur. There is a more comprehensive list of these events here . Here's some example code that show you how to add these events to your chart.

• click
• mousemove
• mouseover
• mouseout

There's more documentation about events available here: Summary of events documentation

<script>
    pie = new RGraph.Pie({
        id: 'cvs',
        data: [4,6,2,4,8,5,8],
        options: {
        }
    }).draw().on('click', function (e, shape)
    {
        // Add your click event listener code here

    }).on('mousemove', function (e, shape)
    {
        // Add your mousemove event listener code here

    }).on('mouseover', function (e, shape)
    {
        // Add your mouseover event listener code here

    }).on('mouseout', function (obj)
    {
        // Add your mouseout event listener code here
    });
</script>

The Horseshoe meter

The Horseshoe meter is now (as of version 5.28) its own chart type and you can read about it on the Horseshoe meter documentation page .

The Segmented donut

The Segmented donut is now (as of version 5.28) its own chart type and you can read about it on the Segmented donut documentation page .

The Activity meter

The Activity meter is now (as of version 5.28) its own chart type and you can read about it on the Activity meter documentation page .

The RadialProgress meter

The RadialProgress can be achieved by using the Activity meter class and configuring it as shown on the Activity meter documentation page.

Animation effects

• The Grow effect (effects-pie-grow.html in the download archive)
• The Explode effect (effects-pie-explode.html in the download archive)
• The RoundRobin effect (effects-pie-roundrobin.html in the download archive)

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

    new RGraph.Pie({
        id: 'cvs',
        data: [8,6,6,5,3,4,2],
        options: {
        }
    }).grow({frames: 60}, myCallback)
    // .implode({frames: 60}, myCallback)
    // .roundRobin({frames: 60}, myCallback)
</script>