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RGraph: HTML5 canvas graph library - Rose chart documentation

The example file is here.

<script>
    window.onload = function ()
    {
        var data = [41,37,16,3,3];
    
        var rose = new RGraph.Rose('myRose', data);
        rose.Set('chart.labels', ['MSIE 7 (41%)',
                                  'MSIE 6 (37%)',
                                  'Firefox (16%)',
                                  'Safari (3%)',
                                  'Other (3%)']);
        rose.Draw();
    }
</script>

Properties
Methods

Properties

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

myRose.Set('name', 'value');

Chart configuration
Margins
Colors
Labels and text
Titles
Axis properties
Scale
Key
Interactive features
Zoom
Miscellaneous

Chart configuration

chart.width
This controls the width of the graph. You can set this to (for example) 600 and have your canvas 650px wide giving an extra 50px for labels.
Default: null (By default the canvas width is used)

chart.height
This controls the height of the graph. You can set this to (for example) 250 and have your canvas 300px heigh giving an extra 50px for labels.
Default: null (By default the canvas height is used)

Margins

chart.gutter
The gutter used on the chart
Default: 25

Colors

chart.colors
An array of colors to be used by the chart.
Default: ['rgb(255,0,0)', 'rgb(0,255,255)', 'rgb(0,255,0)', 'rgb(127,127,127)', 'rgb(0,0,255)', 'rgb(255,128,255)']

chart.colors.alpha
Instead of using rgba(), you can use color definitions such as red along with this setting to add transparency.
Default: null

Labels and text

chart.text.font
The font used to render the text.
Default: Verdana

chart.text.color
The color of the labels.
Default: black

chart.text.size
The size of the text (in points).
Default: 10

chart.labels
The labels, if any, for the graph.
Default: none

chart.labels.axes
This controls the axes that show the scale labels. Each letter stands for the appropriate axis (North, South, East and West)
Default: nsew

chart.labels.position
This can be either center or edge and determines the position of the labels.
Default: center

Titles

chart.title
The title of the chart.
Default: none

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

chart.title.color
The color of the title.
Default: black

chart.title.hpos
This allows you to completely override the horizontal positioning of the title. It should be a number between 0 and 1, and is multiplied with the whole width of the canvas and then used as the horizontal position.
Default: null

chart.title.vpos
This allows you to completely override the vertical positioning of the title. It should be a number between 0 and 1, and is multiplied with the gutter and then used as the vertical position. It can be useful if you need to have a large gutter.
Default: null

Axis properties

chart.ymax
This can be set to control the maximum value of the scale. It's so called to maintain a degree of API compatibility across graph libraries.
Default: null

Scale

chart.scale.round
Whether to round the maximum scale value up or not. This will produce slightly better scales in some instances.
Default: null

Key

chart.key
An array of key information.
Default: [] (An empty array)

chart.key.background
The color of the key background. Typically white, you could set this to something like rgba(255,255,255,0.7) to allow people to see things behind it.
Default: white

chart.key.halign
Instead of specifying the exact x/y coordinates, you can use this property to simply specify whether the key hould be aligned left or right.
Default: right

chart.key.position
Determines the position of the key.Either graph (default), or gutter.
Default: graph

chart.key.position.x
This allows you to specify a specific X coordinate for the key.
Default: null

chart.key.position.y
This allows you to specify a specific Y coordinate for the key.
Default: null

chart.key.position.gutter.boxed
If you have the key in gutter mode (ie horizontal), this allows you to give a background color.
Default: true

chart.key.shadow
Whether a small drop shadow is applied to the key.
Default: false

chart.key.shadow.color
The color of the shadow.
Default: #666

chart.key.shadow.blur
The extent of the blurring effect used on the shadow.
Default: 3

chart.key.shadow.offsetx
The X offset of the shadow.
Default: 2

chart.key.shadow.offsety
The Y offset of the shadow.
Default: 2

chart.key.rounded
This controls whether the corners of the key (in graph mode) are curved. If the key is gutter mode, this has no effect.
Default: false

chart.key.color.shape
This can be square, circle or line and controls how the color indicators in the key appear.
Default: square

chart.key.linewidth
The line width of the surrounding border on the key.
Default: 1

Interactive features

chart.tooltips
An array of tooltips. You can use HTML if you so wish.
Default: [] (An empty array)

chart.tooltips.effect
The tooltip effect used. Can be either fade or expand.
Default: fade

chart.tooltips.css.class
This is the name of the CSS class the graph uses.
Default: RGraph_tooltip

chart.tooltips.override
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

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

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

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

chart.resizable
Defaulting to false, this determines whether your graph 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).
Default: false

chart.resize.handle.adjust
If you're right aligning your chart then you may need this to adjust the position of the resize handle.
Default: [0,0]

chart.resize.handle.background
With 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.
Default: null

chart.adjustable
Defaulting to false, this determines whether your rose chart will be adjustable (click the edge of a segment and drag to adjust it).
Default: false

Zoom

chart.zoom.mode
Can be used to control whether the zoom is in thumbnail or canvas mode. Possible values are: thumbnail and canvas.
Default: canvas

chart.zoom.factor
This is the factor that the graph will be zoomed by (bigger values means more zoom)
Default: 1.5

chart.zoom.fade.in
Whether the zoomed canvas fades in or not. This also can be used to control the fade in for the zoom in thumbnail mode.
Default: true

chart.zoom.fade.out
Whether the zoomed canvas fades out or not. This also can be used to control the fade in for the zoom in thumbnail mode.
Default: true

chart.zoom.hdir
The horizontal direction of the zoom. Possible values are: left, center, right
Default: right

chart.zoom.vdir
The vertical direction of the zoom. Possible values are: up, center, down
Default: down

chart.zoom.delay
The delay (in milliseconds) between frames.
Default: 50

chart.zoom.frames
The number of frames in the zoom animation.
Default: 10

chart.zoom.shadow
Whether or not the zoomed canvas has a shadow or not.
Default: true

chart.zoom.thumbnail.width
When the zoom is in thumbnail mode, this is the width (in pixels) of the thumbnail.
Default: 75

chart.zoom.thumbnail.height
When the zoom is in thumbnail mode, this is the height (in pixels) of the thumbnail.
Default: 75

chart.zoom.background
Defaulting to true, this determines whether the zoom has a dark, semi-opaque background that covers the entire web page.
Default: true

Miscellaneous

chart.highlight.stroke
If you use tooltips, this controls the colour of the highlight stroke.
Default: black

chart.highlight.fill
If you use tooltips, this controls the colour of the highlight fill.
Default: rgba(255,255,255,0.5)

Methods

obj.getSegment()

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

Originating X coordinate
Originating Y coordinate
The radius of the segment
The starting angle (in degrees)
The ending angle (in degrees)

<script>
    RGraph.Register(myGraph);
    
    myGraph.canvas.onclick = function (e)
    {
        RGraph.FixEventObject(e);
        RGraph.Redraw();

        var canvas  = e.target;
        var context = canvas.getContext('2d');
        var obj     = canvas.__object__;
        var segment = obj.getSegment(e);
        
        if (segment) {
            context.fillStyle = 'rgba(255,255,255,0.5)';
            context.beginPath();
                
                // Angles are provided in degrees, so convert them to radians
                segment[3] /= 57.29;
                segment[4] /= 57.29;
            
                context.moveTo(segment[0], segment[1]);
                context.arc(segment[0], segment[1], segment[2], segment[3], segment[4], 0);
            context.stroke();
            context.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 (6th March 2011) been moved to be part of the Pie chart object.