Pie chart API reference

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

<script>
    data = [564,155,499,611,322];

    new RGraph.Pie({
        id: 'cvs',
        data: data,
        options: {
            labels: ['Abc', 'Def', 'Ghi', 'Jkl', 'Mno'],
            linewidth: 2,
            colorsStroke: 'white'
        }
    }).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

PropertyDescriptionDefault
centerxIf required, you can position the Pie chart using this instead of the margins.null
centeryIf required, you can position the Pie chart using this instead of the margins.null
radiusIf required, you can size the Pie chart using this instead of the margins.null

Margin properties

PropertyDescriptionDefault
marginLeftThe left margin of the chart, (the margin is where the labels and title are)).25
marginRightThe right margin of the chart, (the margin is where the labels and title are).25
marginTopThe top margin of the chart, (the margin is where the labels and title are).25
marginBottomThe bottom margin of the chart, (the margin is where the labels and title are).25

Color properties

PropertyDescriptionDefault
colorsColors to be used for the pie segments.['rgb(255,0,0)', '#ddd', 'rgb(0,255,0)', 'rgb(0,0,255)', 'rgb(255,255,0)', 'rgb(0,255,255)', 'red', 'pink', 'black', 'white']
colorsStrokeThe color of the separating lines. This can also be an array of different colors - eg pie.set('colorsStroke', ['red', 'blue', 'green']);.#999

Labels and text properties

PropertyDescriptionDefault
textAccessibleA new feature in 2016 that allows you to use DOM text in place of canvas text. It makes for much higher quality text that you can also select if desired (for copy/paste operations). It won't fit all situations and you can read more about the DOM text feature here. A good way to control borders/margins/padding etc is not to set them on the canvas but to wrap the canvas in a div and set them on that like this:
<div style="margin-left: 50px; display: inline-block">
<canvas id="cvs" width="650" height="250"></canvas>
</div>
true
textAccessibleOverflowThis can be visible or hidden and it controls whether the text is clipped to the edges of the canvas. It defaults to be visible and means you can set small margins if you wish.visible
textAccessiblePointereventsThis controls whether the DOM text responds to mouse based events or not (it sets the pointer-events CSS property to none).true
textSizeThe size of the text.10
textFontThe font used to render the text.Arial, Verdana, sans-serif
textColorThe color of the labels.black
textItalicWhether the text on the chart is italic or not.false
textBoldWhether the text on the chart is bold or not.false
labelsAn array of labels to be used for the chart.An empty array
labelsFontThe font used to render the labels.null
labelsSizeThe size of the labels.null
labelsColorThe color of the labels.null
labelsBoldWhether the labels are bold or not.null
labelsItalicWhether the labels are italic or not.null
labelsSticksLinewidthSets the linewidth of the label sticks.1
labelsListA new way of organising the labels - this should help avoid label text overlaps.true
labelsIngraphThis shows in-graph labels in each segment.null
labelsIngraphBoundingWhether the in-graph labels are surrounded by a bounding box.false
labelsIngraphBoundingFillThe fill color of the bounding square.white
labelsIngraphBoundingStrokeThe stroke color of the bounding square.rgba(0,0,0,0)
labelsIngraphUnitsPreThis string is prepended to the label.(empty string)
labelsIngraphUnitsPostThis string is appended to the label.(empty string)
labelsIngraphRadiusIf specified this is the radius that the labels are positioned at. If it's a number between 0 and 2 it is multiplied with the radius to get the position. If it's above 2 though it's used as the exact radius.null
labelsIngraphPointThe character used as the decimal point..
labelsIngraphThousandThe character used as the thousand separator.,
labelsIngraphDecimalsThe number of decimals shown on the ingraph labels.0
labelsIngraphColorThe color of the labels.null
labelsIngraphFontThe font to use for the ingraph labels.null
labelsIngraphSizeThe size of the ingraph labels.null
labelsIngraphBoldWhether the ingraph labels are bold or not.null
labelsIngraphItalicWhether the ingraph labels are italic or not.null
labelsIngraphSpecificInstead of the values you use this option to specify the text that is shown.null
labelsCenterIf you have a donut chart this can show a label in the center. As of version 4.75 This should be a literal string - ie the label that you want to show.false
labelsCenterSizeThe size of the center label.26
labelsCenterFontThe font used to render the label.Arial
labelsCenterColorThe color of the center label.black
labelsCenterItalicWhether the center label is italic.false
labelsCenterBoldWhether the center label is bold.false

Title properties

PropertyDescriptionDefault
titleThe title of the pie chart.none
titleFontThe font that the title is rendered in. If not specified the textFont setting is used (usually Arial).null
titleSizeThe size of the title. If not specified the size is usually 2pt bigger than the textSize setting.null
titleBoldWhether the title is bold or not.true
titleItalicWhether the title is italic or not.false
titleBackgroundThe background color (if any) for the title.null
titleColorThe color of the title.black
titleXTo give the exact X coordinate for the title - use this. This can also be a string like this: "-5" -- in which case it's converted to a number and added to the calculated coordinate - allowing you to adjust the calculated coordinate.null
titleYTo give the exact Y coordinate for the title - use this. This can also be a string like this: "-5" -- in which case it's converted to a number and added to the calculated coordinate - allowing you to adjust the calculated coordinate.null

Shadow properties

PropertyDescriptionDefault
shadowWhether a drop shadow is applied.true
shadowColorThe color of the shadow.#aaaa
shadowOffsetxThe X offset of the shadow.0
shadowOffsetyThe Y offset of the shadow.0
shadowBlurThe severity of the shadow blurring effect.15

Interactive features properties

PropertyDescriptionDefault
tooltipsA numerically indexed array of tooltips that are shown when a bar is clicked. These can contain HTML.[]
tooltipsEventThis is the event that triggers the tooltips. It can be either click or mousemove.click
tooltipsEffectThe effect used for showing tooltips. Can be either fade or none.fade
tooltipsCssClassThis is the name of the CSS class the chart uses.RGraph_tooltip
tooltipsOverrideIf you wish to handle showing tooltips yourself, this should be a function object which does just that. There's more information on the tooltips documentation page.null
tooltipsNohideonclearNot an option that you'll need particularly often if at all. Setting this to true means that when you call the RGraph.clear() API function tooltips do not get hidden.false
contextmenuAn array of context menu items. More information about context menus is here.[] (An empty array)
annotatableWhether annotations are enabled for the chart (ie you can draw on the chart interactively.false
annotatableColorIf you do not allow the use of the palette, then this will be the only color allowed for annotations.black
annotatableLinewidthThis is the linewidth of the annotations.1
resizableDefaulting to false, this determines whether your chart will be resizable. Because of the numerous event handlers this has to install code on, This feature is unlikely to work with other dynamic features (the context menu is fine however).false
resizableHandleBackgroundWith this you can specify the background color for the resize handle. If you're adjusting the position of the handle then you may need this to make the handle stand out more.null
resizableMinwidthThis allows you to set a minimum width that the chart can be resized to.null
resizableMinheightThis allows you to set a minimum height that the chart can be resized to.null
resizableMaxwidthThis allows you to set a maximum width that the chart can be resized to.null
resizableMaxheightThis allows you to set a maximum height that the chart can be resized to.null

Key properties

The key properties are documented on the key documentation page.

Event properties

PropertyDescriptionDefault
eventsClickIf you want to add your own click function you can do so by assigning it to this property. See here for details.null
eventsMousemoveIf you want to add your own mousemove function you can do so by assigning it to this property. See here for details.null
eventsMouseoverIf you want to add your own mouseover function you can do so by assigning it to this property. See here for details.null
eventsMouseoutIf you want to add your own mouseout function you can do so by assigning it to this property. See here for details.null

Miscellaneous properties

PropertyDescriptionDefault
linewidthBy setting this to roughly 5, and setting the colorsStroke to the same color as your background color you will get a segment separation effect.1
variantThis can be either pie (the default), pie3d, donut or donut3d. Setting this to donut or donut3d is how you get a donut chart.pie
variantThreedDepthThis is the depth of the 3D Pie chart.20
variantDonutWidthThis allows you to set how wide the donut is. It can be useful when nesting donuts.null
highlightStyleCan be either 2d, 3d, outline or a function and determines which style of segment highlighting is used in conjunction with tooltips. If its a function the function is called and no highlighting is done - ie you should do it all yourself.2d
highlightStyleOutlineWidthWhen outline highlighting for tooltips is used, this controls the width of the highlighting band.10
highlightStyleTwodFillWhen 2D highlighting for tooltips is used, this controls the color of the highlighting. The former name for this property was highlightStyleTwodColor.rgba(255,255,255,0.5)
highlightStyleTwodStrokeWhen 2D highlighting for tooltips is used, this controls the stroke color of the highlighting.rgba(255,255,255,0)
explodedThis can either be an array with the same number of elements as segments, or a single number, in which case every segment will be exploded that amount. If it's an array then only those segments will be exploded - eg [0,5,0,0]An empty array
centerpinBy using a centerpin you can add a circle to the center of your charts. This setting should be a number and is used as the radius of the centerpin.null
centerpinStrokeThis is used as the stroke style of the centerpin.null
centerpinFillThis is used as the fill style of the centerpin.null
cleartoThis is used in animations and effects as the default color to use when the canvas.null

Methods

obj.get(name)
An accessor that you can use to retrieve the values of properties.

obj.set(name, value)
An accessor that you can use to set the values of properties.

obj.getShape(event)

obj.getSegment() makes it easy to determine which segment of the Pie chart was clicked on. It provides:

The shape also includes textual indexes like this: shape['object'] And they are:

<script>
    RGraph.register(myGraph);
    
    myGraph.canvas.onclick = function (e)
    {
        RGraph.fixEventObject(e);
        RGraph.redraw();

        var ca  = e.target;
        var co  = ca.getContext('2d');
        var obj = ca.__object__;
        var segment = obj.getShape(e);
        
        if (segment) {
            co.fillStyle = 'rgba(255,255,255,0.5)';
            co.beginPath();            
                co.moveTo(segment[0], segment[1]);
                co.arc(segment[0], segment[1], segment[2], segment[3], segment[4], 0);
            co.stroke();
            co.fill();
            
            e.stopPropagation();
        }
    }
    
    window.onclick = function (e)
    {
        RGraph.redraw();
    }
</script>
Important Note

This method was formerly a common object method, called RGraph.getSegment(e), but has now (March 2011) been moved to be part of the Pie chart object.

obj.explodeSegment(index, size)

The explodeSegment() 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.explodeSegment(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.

obj.getAngle(value)

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).

obj.on(event, function)

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 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 (e, shape)
{
    // Put your ondraw code here
}).on('click', function (e, shape)
{
    // Handle the click event
}).draw()
The exec option and method

The exec function is documented here.

Animation effects

These effects are available and can be used instead of the draw() function. There are also generic effects available which you can see here: Generic effects and transitions
<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>