About
RGraph is a JavaScript charts library based on HTML5 SVG and canvas. RGraph is mature (over 15 years old) and has a wealth of features making it an ideal choice to show charts on your website.

More »

 

License
RGraph can be used for free under the GPL or if that doesn't suit your situation there's an inexpensive (£99) commercial license available.

More »

 

Download
Get the latest version of RGraph (version 6.16) from the download page. There's also older versions available, minified files and links to cdnjs.com hosted libraries.

More »

Activity meter

Example

An animated Activity meter showing three values
<script>
    activity = new RGraph.Activity({
        id: 'cvs',
        min: 0,
        max: 100,
        value: [12,38,65],
        options: {
            width: 30,
            labelsCenter: true,
            marginLeft: 5,
            marginRight: 5,
            marginTop: 5,
            marginBottom: 5
        }
    }).grow();
    

    setInterval(function ()
    {
        for (var i=0,rand=[]; i<3; ++i) {
            rand[i] = RGraph.random(-10,10);
            activity.value[i] += rand[i];
        }
    
        activity.grow();
    },2500);
</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 shown above.

Chart configuration properties

Name: centerx
Description: 
The X coordinate of the meter.
Default: null (the horizontal center of the canvas)
Name: centery
Description: 
The Y coordinate of the meter.
Default: null (the vertical center of the canvas)
Name: radius
Description: 
The radius of the chart.
Default: null (this is generated based on the size of the canvas)
Name: width
Description: 
This is the width of the circular bars that make up the chart.
Default: null

Margin properties

Name: marginLeft
Description: 
The left margin of the chart.
Default: 15
Name: marginRight
Description: 
The right margin of the chart.
Default: 15
Name: marginTop
Description: 
The top margin of the chart.
Default: 15
Name: marginBottom
Description: 
The bottom margin of the chart.
Default: 15
Name: marginInner
Description: 
The margin on either side of the indicator bar.
Default: 1

Background properties

Name: backgroundGridColor
Description: 
The color of the background grid.
Default: #666
Name: backgroundGridCircles
Description: 
Whether the background grid circular lines are enabled.
Default: false
Name: backgroundGridCirclesCount
Description: 
The number of background grid circular lines. By default, this number is dependent on how many values you're showing on the chart.
Default: null
Name: backgroundGridRadials
Description: 
Whether the background grid radial lines are enabled (the lines that emanate from the center and go outwards).
Default: true
Name: backgroundGridRadialsCount
Description: 
The number of background grid radial lines.
Default: 8
Name: backgroundRings
Description: 
Whether the background rings are drawn. These are the rings that serve as backgrounds to the bars.
Default: true
Name: backgroundRingsColors
Description: 
If you wish you can stipulate the exact colors for the background rings with this property..
Default: null
Name: backgroundRingsAlpha
Description: 
The alpha value (ie the transparency) of the colors of the background rings.
Default: 0.5

Color properties

Name: backgroundColor
Description: 
The background color of the canvas.
Default: black
Name: colors
Description: 
The colors of the indicator bars. These can be solid colors or gradients.
Default: [#f45b5b, #90ee7e, #2b908f, red, green, blue, yellow, pink]

Labels and text properties

Name: textAccessible
Description: 
A new feature in 2016 that allows you to use dom text in place of canvas text. It makes for a 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: false
Name: textAccessibleOverflow
Description: 
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
Name: textAccessiblePointerevents
Description: 
This controls whether the dom text responds to mouse-based events or not (it sets the pointer-events css property to none).
Default: true
Name: textFont
Description: 
The font used to render the text.
Default: Arial, Verdana, sans-serif
Name: textColor
Description: 
The color of the label.
Default: #aaa
Name: textSize
Description: 
The size of the text (in points).
Default: 12
Name: textBold
Description: 
Whether the text on the chart is bold or not.
Default: false
Name: textItalic
Description: 
Whether the text on the chart is italic or not.
Default: false
Name: labels
Description: 
Labels are placed to the left of the start of the bars (at the top middle). You can also give this option a string if you prefer and use formatted labels
Default: [] (an empty array)
Name: labelsFont
Description: 
The font used by the labels.
Default: null
Name: labelsSize
Description: 
The size of the labels.
Default: null
Name: labelsColor
Description: 
The color of the labels.
Default: null
Name: labelsBold
Description: 
Whether the labels are bold or not.
Default: null
Name: labelsItalic
Description: 
Whether the labels are italic or not.
Default: null
Name: labelsBackgroundFill
Description: 
With this you can give a color for the background fill to the labels.
Default: null
Name: labelsBackgroundStroke
Description: 
With this you can give a color for the background stroke to the labels.
Default: null
Name: labelsOffsetx
Description: 
This allows you finer-grained control in the horizontal direction over the text positioning if you need it.
Default:  0
Name: labelsOffsety
Description: 
This allows you finer-grained control in the vertical direction over the text positioning if you need it.
Default:  0
Name: labelsFormattedDecimals
Description: 
When using formatted labels this is the number of decimals that are applied to the %{value_formatted} macro.
Default:  0
Name: labelsFormattedPoint
Description: 
When using formatted labels this is the decimal point character that's used with the %{value_formatted} macro.
Default: .
Name: labelsFormattedThousand
Description: 
When using formatted labels this is the thousand separator character that's used with the %{value_formatted} macro.
Default: ,
Name: labelsFormattedUnitsPre
Description: 
When using formatted labels these are the units that are prepended to the number with the %{value_formatted} macro.
Default: (an empty string)
Name: labelsFormattedUnitsPost
Description: 
When using formatted labels these are the units that are appended to the number with the %{value_formatted} macro.
Default: (an empty string)
Name: labelsCenter
Description: 
Whether the center label is drawn or not.
Default: false
Name: labelsCenterIndex
Description: 
This is the index that corresponds to the index of the relevant ring's value that you want to display.
Default:  0
Name: labelsCenterFont
Description: 
The font of the center label.
Default: null
Name: labelsCenterSize
Description: 
The size of the center label.
Default: 50
Name: labelsCenterColor
Description: 
The color of the center label.
Default: null
Name: labelsCenterBold
Description: 
Whether the center label is bold or not.
Default: null
Name: labelsCenterItalic
Description: 
Whether the center label is italic or not.
Default: null
Name: labelsCenterUnitsPre
Description: 
Units that are prepended to the value.
Default: [an empty string]
Name: labelsCenterUnitsPost
Description: 
Units that are appended to the value.
Default: [an empty string]
Name: labelsCenterDecimals
Description: 
The number of decimals that are shown.
Default:  0
Name: labelsCenterPoint
Description: 
The character that's used as the decimal point.
Default: .
Name: labelsCenterThousand
Description: 
The character that's used as the thousand separator.
Default: ,
Name: labelsCenterSpecific
Description: 
If you want to specify the exact label to show you can do so with this property.
Default: [an empty string]
Name: labelsCenterOffsetx
Description: 
This allows you finer-grained control in the horizontal direction over the text positioning if you need it.
Default:  0
Name: labelsCenterOffsety
Description: 
This allows you finer-grained control in the vertical direction over the text positioning if you need it.
Default:  0
Name: text
Description: 
This allows you to add custom text to your chart if you want to. There's a dedicated page that describes this option here.
Default: null

Interactive features properties

Name: tooltips
Description: 
A numerically indexed array of tooltips that are shown when a bar is clicked. These can contain html.
Default: null
Name: tooltipsEffect
Description: 
The effect used for showing tooltips. Can be either slide fade or none.
Default: slide
Name: tooltipsEvent
Description: 
This is the event that triggers the tooltips. It can be either click or mousemove.
Default: click
Name: tooltipsOverride
Description: 
If you wish to handle showing tooltips yourself, this should be a function that does just that. There's more information on the tooltips documentation page.
Default: null
Name: tooltipsHighlight
Description: 
Set this to false if you don't want your charts to be highlighted.
Default: true
Name: tooltipsFormattedPoint
Description: 
When using formatted tooltip strings this is used as the point when using the %{value_formatted} option.
Default: .
Name: tooltipsFormattedThousand
Description: 
When using formatted tooltip strings this is used as the thousand separator when using the %{value_formatted} option.
Default: ,
Name: tooltipsFormattedDecimals
Description: 
When using formatted tooltip strings this specifies the number of decimals when using the %{value_formatted} option.
Default:  0
Name: tooltipsFormattedUnitsPre
Description: 
When using formatted tooltip strings these units are prepended to the number when using the %{value_formatted} option.
Default: (an empty string)
Name: tooltipsFormattedUnitsPost
Description: 
When using formatted tooltip strings these units are appended to the number when using the %{value_formatted} option.
Default: (an empty string)
Name: tooltipsFormattedKeyColors
Description: 
When using formatted tooltip strings you can give specific colors for the %{key} option to use.
Default: null
Name: tooltipsFormattedKeyColorsShape
Description: 
This is the shape that's used in the tooltip key. It can be square or circle
Default: square
Name: tooltipsFormattedKeyColorsCss
Description: 
By using this property you can add css values to the key color shape that appears in the tooltip key. Note the property name is "color" and not "colors" like previous properties. It should be an object of css properties like this:
tooltipsFormattedKeyColorsCss : {
    border: "1px solid #ddd";
}
Default: null
Name: tooltipsFormattedKeyLabels
Description: 
When using formatted tooltip strings these are the labels that are displayed.
Default: [] (an empty array)
Name: tooltipsFormattedListType
Description: 
With this property you can switch between an unordered list (the default) and an ordered list. Possible values are ul and ol.
Default: ul
Name: tooltipsFormattedListItems
Description: 
This should be a two-dimension array of the list items that are to be shown for all of the tooltips. An example of this property is:
tooltipsFormattedListItems: [
    ['Bill','Jerry','Berty'], // First tooltip
    ['Gill','Carrie','Lucy'], // Second tooltip
    ['Pob','Nobby','Hilda']   // Third tooltip
]
You can use css to style this list - for example:
.RGraph_tooltip ul#rgraph_formatted_tooltips_list li {
    text-align: left;
    color: yellow;
}
Default: null
Name: tooltipsFormattedTableHeaders
Description: 
When showing a table in the tooltips this can be an array of headers for the table. These are added to the tooltip using th tags.
Default: null
Name: tooltipsFormattedTableData
Description: 
This is the data that is added to the table. This is a 3-dimensional array so it's easy to make a mistake. See the example, copy the code from it and then modify it suit. You'll create fewer bugs this way.
Default: null)
Name: tooltipsPointer
Description: 
By default the tooltips have a small triangular pointer that points to the shape that was clicked on. You can turn this off with this property.
Default: true
Name: tooltipsPointerCss
Description: 
If you want any css values applied to the tooltips pointer (for example a css border) then specify an object containing those values to this property. For example:
tooltipsPointerCss: {
    borderLeft: 'gray 2px solid',
    borderBottom: 'gray 2px solid'
}
Default: null
Name: tooltipsPointerOffsetx
Description: 
This allows you to adjust the vertical position of the tooltips pointer.
Default:  0
Name: tooltipsPointerOffsety
Description: 
This allows you to adjust the vertical position of the tooltips pointer (for example, if you add a border you may need to move it down slightly).
Default:  0
Name: tooltipsPositionStatic
Description: 
The new default (as of August 2020) is for tooltips to be positioned statically and not be dependent on the mouse position. If you don't want this for whatever reason, you can disable it with this setting. When you set it to false tooltips are positioned next to the mouse pointer.
Default: true
Name: tooltipsCss
Description: 
If you want to specify some css that gets applied to all of the tooltips, but don't want to use the RGraph.tooltips.style object (which gets applied to all of the tooltips on the page for every chart) you can use this property to give some per-object css for the tooltips. These are css styles that get applied to all of the tooltips for the specific object only. It should look like this:
tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt',
    backgroundColor: 'black',
    color: 'white'
}
Default: null
Name: tooltipsCssClass
Description: 
This is the name of the css class the chart uses.
Default: RGraph_tooltip
Name: tooltipsOffsetx
Description: 
This property allows you to shift the tooltips left or right.
Default:  0
Name: tooltipsOffsety
Description: 
This property allows you to shift the tooltips up or down.
Default:  0
Name: tooltipsHotspotIgnore
Description: 
This can be a number of things and can be used to ignore certain tooltip hotspots - which can allow charts to the rear to be clickable. There's an example of this in the download archive called pie-tooltipshotspotignore.html. You can use the transparent color to allow the rear chart to be seen in such a case. It can be:
  • A single boolean value (ie true or false) to enable or disable all of the hotspots - true means the hotspot will be ignored
  • A single number (the zero-indexed number corresponding to the hotspot to ignore)
  • An array of numbers (the numbers are the indexes of hotspots to ignore)
  • An array of boolean true or false values - the position of these values correspond to the index(es) of the segments to ignore (for example [false, false, true, false, false] - true means the corresponding hotspot will be ignored)
Default: null
Name: contextmenu
Description: 
An array of context menu items. More information about context menus is here.
Default: null
Name: annotatable
Description: 
Whether annotations are enabled for the chart (ie you can draw on the chart interactively.
Default: false
Name: annotatableColor
Description: 
If you do not allow the use of the palette, then this will be the only color allowed for annotations.
Default: black
Name: annotatableLinewidth
Description: 
This is the linewidth of the annotations.
Default: 1
Name: adjustable
Description: 
Defaulting to false, this determines whether your meter will be adjustable (click the bars and drag them).
Default: false

Miscellaneous properties

Name: highlight.style
Description: 
By default this is null but you can set it to a function if you wish so that function is called to do the chart highlighting. It's passed the shape object as an argument. As of version 5.23 you can also set this to invert as well. If you do this on a dark background you may find that you need to change the highlightFill color setting as well.
Default: null
Name: highlight.stroke
Description: 
If you use tooltips, this controls the color of the highlight stroke.
Default: rgba(0,0,0,0)
Name: highlight.fill
Description: 
If you use tooltips, this controls the color of the highlight fill.
Default: rgba(255,255,255,0.5)
Name: icons
Description: 
This can be an array of filenames (including their paths) of icons that are placed at the start of each bar. Eg ['/images/first.png', '/images/second.png', '/images/third.png']
Default: []
Name: iconsWidth
Description: 
With this you can give a specific width for the images.
Default: null
Name: iconsHeight
Description: 
With this you can give a specific height for the images.
Default: null
Name: iconsOffsetx
Description: 
This should be a number (either positive or negative) that is added to the X coordinate of the image.
Default:  0
Name: iconsOffsety
Description: 
This should be a number (either positive or negative) that is added to the Y coordinate of the image.
Default:  0
Name: ends
Description: 
This determines whether the ends of the bars will be round or straight. Possible values are: round straight and square
Default: round
Name: clearto
Description: 
This is used in animations and effects as the default color to use when clearing the canvas.
Default: null
Name: responsive
Description: 
This option is new to the July 2023 release (v6.13) and allows you to inline the responsive configuration instead of appending it on to the end of the object it as a function. The documentation and demo pages have been updated to use this new option. You can read more about the responsive feature by reading the responsive configuration page.
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 bar has been clicked on or hovered over. It returns an object which has the following indexes available:
object The chart object
x The center X coordinate
y The center Y coordinate
angleStart The start angle of the segment.
angleEnd The end angle of the segment.
radiusInner The inside radius of the segment.
radiusOuter The outside radius of the segment.
label The relevant label for this ring.
tooltip If a tooltip is associated with this bar or 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).
dataset This is always zero.
index The zero-indexed numerical index of the bar.
sequentialIndex The zero-indexed sequential index of the bar.
<script>
    obj.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,
                start       = shape.angleStart,
                end         = shape.angleEnd,
                radiusInner = shape.radiusInner,
                radiusInner = shape.radiusOuter;
            
            obj.path(
                'b    a % % % % % false    a % % % % % true    s black f red',
                x, y, radiusInner, start, end,
                x, y, radiusOuter, end, start
            );
        }
    }
</script>

obj.getValue(event)

This method can be used to get the value at a particular point when you click on the chart. An example:

obj.canvas.onclick = function (e)
{
    var obj   = e.target.__object__;
    var value = obj.getValue(e);
    
    // ...
}

obj.getAngle(value)
This method will return you an appropriate angle for the given value.

obj.getIndexByRadius(radius)
This method will return the index that corresponds to the ring that you're currently hovering over or clicking on.

obj.on(event, function)

This method can be used to set an event listener on an object. It operates similarly 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 event code here
});

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

var obj = new RGraph.Activity({
    id: 'cvs',
    min: 0,
    max: 100,
    value: [25,35,46],
    options: {
    }
}).on('draw', function (e, shape)
{
    // Put the draw event code here
})
.on('click', function (e, shape)
{
    // Handle the click event
}).draw();
obj.exec(function)

The exec function is documented here.


obj.responsive(configuration)

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.

Update: There is now the responsive configuration option available to you and this is now the preferred method of configuration.

The responsive function and configuration option are documented on their own page here.

Events

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

For example:
new RGraph.Activity({
    id: 'cvs',
    min: 0,
    max: 100,
    value:[26,35,34],
    options: {
    }
}).on('draw', function (obj)
{
    console.log('The draw event has fired');
    
}).draw();

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)
    {
        // ...
    }

    obj = new RGraph.Activity({
        id: 'cvs',
        min: 0,
        max: 100,
        value: 56,
        options: {
        }
    }).grow({frames: 60}, myCallback)
</script>