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

<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
centerx
If required, you can position the Pie chart using this instead of the margins.
Default: null

centery
If required, you can position the Pie chart using this instead of the margins.
Default: null

radius
If required, you can size the Pie chart using this instead of the margins.
Default: 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
marginLeft
The left margin of the chart, (the margin is where the labels and title are)).
Default: 25

marginRight
The right margin of the chart, (the margin is where the labels and title are).
Default: 25

marginTop
The top margin of the chart, (the margin is where the labels and title are).
Default: 25

marginBottom
The bottom margin of the chart, (the margin is where the labels and title are).
Default: 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
colors
Colors to be used for the pie segments.
Default: ['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']

colorsStroke
The color of the separating lines. This can also be an array of different colors - eg pie.set('colorsStroke', ['red', 'blue', 'green']);.
Default: #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.false
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
labelsCenterThis can show a label in the center of the chart. This should be a string - ie the label that you want to show.[An empty string]
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
textAccessible
A 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>

Default: true

textAccessibleOverflow
This 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.
Default: visible

textAccessiblePointerevents
This controls whether the DOM text responds to mouse based events or not (it sets the pointer-events CSS property to none).
Default: true

textSize
The size of the text.
Default: 10

textFont
The font used to render the text.
Default: Arial, Verdana, sans-serif

textColor
The color of the labels.
Default: black

textItalic
Whether the text on the chart is italic or not.
Default: false

textBold
Whether the text on the chart is bold or not.
Default: false

labels
An array of labels to be used for the chart.
Default: An empty array

labelsFont
The font used to render the labels.
Default: null

labelsSize
The size of the labels.
Default: null

labelsColor
The color of the labels.
Default: null

labelsBold
Whether the labels are bold or not.
Default: null

labelsItalic
Whether the labels are italic or not.
Default: null

labelsSticksLinewidth
Sets the linewidth of the label sticks.
Default: 1

labelsList
A new way of organising the labels - this should help avoid label text overlaps.
Default: true

labelsIngraph
This shows in-graph labels in each segment.
Default: false

labelsIngraphBounding
Whether the in-graph labels are surrounded by a bounding box.
Default: false

labelsIngraphBoundingFill
The fill color of the bounding square.
Default: white

labelsIngraphBoundingStroke
The stroke color of the bounding square.
Default: rgba(0,0,0,0)

labelsIngraphUnitsPre
This string is prepended to the label.
Default: (empty string)

labelsIngraphUnitsPost
This string is appended to the label.
Default: (empty string)

labelsIngraphRadius
If 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.
Default: null

labelsIngraphPoint
The character used as the decimal point.
Default: .

labelsIngraphThousand
The character used as the thousand separator.
Default: ,

labelsIngraphDecimals
The number of decimals shown on the ingraph labels.
Default: 0

labelsIngraphColor
The color of the labels.
Default: null

labelsIngraphFont
The font to use for the ingraph labels.
Default: null

labelsIngraphSize
The size of the ingraph labels.
Default: null

labelsIngraphBold
Whether the ingraph labels are bold or not.
Default: null

labelsIngraphItalic
Whether the ingraph labels are italic or not.
Default: null

labelsIngraphSpecific
Instead of the values you use this option to specify the text that is shown.
Default: null

labelsCenter
This can show a label in the center of the chart. This should be a string - ie the label that you want to show.
Default: [An empty string]

labelsCenterSize
The size of the center label.
Default: 26

labelsCenterFont
The font used to render the label.
Default: Arial

labelsCenterColor
The color of the center label.
Default: black

labelsCenterItalic
Whether the center label is italic.
Default: false

labelsCenterBold
Whether the center label is bold.
Default: 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.null
titleItalicWhether the title is italic or not.null
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
title
The title of the pie chart.
Default: none

titleFont
The font that the title is rendered in. If not specified the textFont setting is used (usually Arial).
Default: null

titleSize
The size of the title. If not specified the size is usually 2pt bigger than the textSize setting.
Default: null

titleBold
Whether the title is bold or not.
Default: null

titleItalic
Whether the title is italic or not.
Default: null

titleBackground
The background color (if any) for the title.
Default: null

titleColor
The color of the title.
Default: black

titleX
To 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.
Default: null

titleY
To 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.
Default: 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
shadow
Whether a drop shadow is applied.
Default: true

shadowColor
The color of the shadow.
Default: #aaaa

shadowOffsetx
The X offset of the shadow.
Default: 0

shadowOffsety
The Y offset of the shadow.
Default: 0

shadowBlur
The severity of the shadow blurring effect.
Default: 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
tooltips
A numerically indexed array of tooltips that are shown when a bar is clicked. These can contain HTML.
Default: []

tooltipsEvent
This is the event that triggers the tooltips. It can be either click or mousemove.
Default: click

tooltipsEffect
The effect used for showing tooltips. Can be either fade or none.
Default: fade

tooltipsCssClass
This is the name of the CSS class the chart uses.
Default: RGraph_tooltip

tooltipsOverride
If 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.
Default: null

tooltipsNohideonclear
Not 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.
Default: false

contextmenu
An array of context menu items. More information about context menus is here.
Default: [] (An empty array)

annotatable
Whether annotations are enabled for the chart (ie you can draw on the chart interactively.
Default: false

annotatableColor
If you do not allow the use of the palette, then this will be the only color allowed for annotations.
Default: black

annotatableLinewidth
This is the linewidth of the annotations.
Default: 1

Key properties

The key properties are documented on the key documentation page.

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 it's 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
linewidth
By setting this to roughly 5, and setting the colorsStroke to the same color as your background color you will get a segment separation effect.
Default: 1

variant
This can be either pie (the default), pie3d, donut or donut3d. Setting this to donut or donut3d is how you get a donut chart.
Default: pie

variantThreedDepth
This is the depth of the 3D Pie chart.
Default: 20

variantDonutWidth
This allows you to set how wide the donut is. It can be useful when nesting donuts.
Default: null

highlightStyle
Can be either 2d, 3d, outline or a function and determines which style of segment highlighting is used in conjunction with tooltips. If it's a function the function is called and no highlighting is done - ie you should do it all yourself.
Default: 2d

highlightStyleOutlineWidth
When outline highlighting for tooltips is used, this controls the width of the highlighting band.
Default: 10

highlightStyleTwodFill
When 2D highlighting for tooltips is used, this controls the color of the highlighting. The former name for this property was highlightStyleTwodColor.
Default: rgba(255,255,255,0.5)

highlightStyleTwodStroke
When 2D highlighting for tooltips is used, this controls the stroke color of the highlighting.
Default: rgba(255,255,255,0)

exploded
This 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]
Default: An empty array

centerpin
By 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.
Default: null

centerpinStroke
This is used as the stroke style of the centerpin.
Default: null

centerpinFill
This is used as the fill style of the centerpin.
Default: null

clearto
This is used in animations and effects as the default color to use when the canvas.
Default: 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)
This method makes it easy to get hold of which segment has been clicked on or hovered over. It returns an object which has the following indexes available:
object The chart object
x This is the center X coordinate for the segment.
y This is the center Y coordinate for the segment.
radius This is the radius of the segment.
angleStart This is the start angle of the segment. It's measured in radians - not degrees. 1 radian = 57.29 degrees.
angleEnd This is the end angle of the segment. It's measured in radians - not degrees. 1 radian = 57.29 degrees.
dataset Since Pie charts can only have one dataset this is always zero.
index The zero-indexed index of the segment on the chart.
sequentialIndex The sequentialIndex is the zero-indexed sequential index of the point on the chart. Since , with Pie charts, there's only ever a single dataset this is always the same as the index value.
tooltip If a tooltip is associated with this segment this will be it. id: strings are expanded for you (where the tooltip text is retrieved from the HTML tag with the matching ID).
<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;

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

obj.explode(index, size)

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.


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 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()

obj.exec(function)

The exec function is documented 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.

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

[No canvas support]

Prior to version 5.02 it was possible to get this type of meter but it involved a lot of code (which you could always have put in a library file).

But now there's a dedicated class for it so it becomes an awful lot easier to create these types of charts. The code looks like this:

<script>
    new RGraph.HorseshoeMeter({
        id: 'cvs_horseshoe',
        min: 0,
        max: 100,
        value: 65,
        options: {
        }
    }).roundRobin();
</script>

The Segmented Meter

[No canvas support]

Prior to version 5.2 it was possible to get this type of meter (there was a demo for it available in the demos folder) but it involved a lot of code so now there's a specialised class for it. The demo for it has been updated with the new code.

So it becomes an awful lot easier to create these types of charts. The code looks like this:

&lt;script&gt;
    segmented = new RGraph.SegmentedMeter({
        id: 'cvs_segmented',
        max: 100,
        value: 70,
        options: {
            //backgroundColor: 'black',
            //value: true,
            //valuePercentage: false,
            //valueUnitsPre: '',
            //valueDecimals: 1,
            //valueBold: null,
            //valueItalic: null,
            //valueFont: null,
            //colors: ['red','white']
            //variantDonutWidth: null,
            valueUnitsPost: '%',
            valueColor: '#aaa',
            valueSize: 50
        }
    }).roundRobin({frames: 60});
&lt;/script&gt;

The Activity Meter

[No canvas support]

Prior to version 5.2 it was possible to get this type of meter (there was a demo for it available in the demos folder) but it involved a lot of code so now there's a specialised class for it. The demo for has been updated with the new code.

So it becomes an awful lot easier to create these types of charts. The code looks like this:

&lt;script&gt;
    // The definitions of the rings, their values, colors and radius.
    activity = new RGraph.ActivityMeter({
        id: 'cvs_activity',
        config: [
            {color: '#2B908F', value: 67, image: '/images/activityMeter-arrowright.png' , _label_: 'A' }, // You can have either a label or an image
            {color: '#90EE7E', value: 57, image: '/images/activityMeter-arrowup.png'   ,  _label_: 'B' }, // You can have either a label or an image
            {color: '#F45B5B', value: 46, image: '/images/activityMeter-arrowdown.png',   _label_: 'C' }  // You can have either a label or an image
        ],
        options: {
            variantDonutWidth: 30,
            marginTop: 5,
            marginBottom: 5,
            marginLeft: 5,
            marginRight: 5,
            labelColor: 'black',
            labelFont: 'Monospace',
            labelSize: 28,
            labelBold: true,
            labelItalic: true
        }
    }).draw();
&lt;/script&gt;

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>