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Radar chart API reference

Example

<script>
    // Some data that's to be shown on the Radar chart. For multiple
    // lines it should be an array of arrays
    // data = [50,57,54,59,56];

    data = [
        [50,58,54,59,56],
        [90,84,86,98,86]
    ];

    new RGraph.SVG.Radar({
        id: 'chart-container',
        data: data,
        options: {
            colors: ['black', 'red'],
            tickmarksStyle: 'circle',
            tickmarksSize: 5,
            linewidth: 2,
            labels: ['John','Jay','June','Jocy','Joseph'],
            labelsBold: true,
            labelsItalic: true,
            labelsSize: 20,
            labelsOffset: 0,
            tooltips: '<i>Results for</i> <b>%{property:labels[%{index}]}</b><br />%{key}',
            tooltipsFormattedKeyLabels: ['Monday:','Tuesday:'],
            tooltipsFormattedUnitsPost:'%',
            tooltipsCss: {
                backgroundColor: '#333',
                fontWeight: 'bold',
                fontSize: '14pt',
                opacity: 0.85
            }
        }
    }).draw();
</script>

The angles (coordinates) properties

The details of the points on the Radar chart are held in two arrays called obj.angles and obj.angles2. The difference is how they're indexed. With the former, each point is appended to the array - so on a Radar chart with two datasets where each consists of eight points - the obj.angles array would result in having 16 elements - one per point.

The obj.angles2 array on the other hand is indexed by the relevant dataset - to which points are appended. So in the previous example, the angles2 array would have two elements - each of them being another array of eight elements (one per point). These elements are objects that consist of the following properties:

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: 
If required, you can position the Radar chart using this instead of the margins. As well as a number, that gives the exact coordinate of the center position of the chart, this can also be a string like this: centerx: '+25' or this: centerx: '-40' which is then used to adjust the calculated coordinate.
Default: null
Name: centery
Description: 
If required, you can position the Radar chart using this instead of the margins. As well as a number, that gives the exact coordinate of the center position of the chart, this can also be a string like this: centery: '+25' or this: centery: '-40' which is then used to adjust the calculated coordinate.
Default: null
Name: radius
Description: 
If required, you can size the Radar chart using this instead of the margins. As well as a number, that gives the exact coordinate of the center position of the chart, this can also be a string like this: radius: '+25' or this: radius: '-40' which is then used to adjust the calculated coordinate.
Default: null

Margin properties

Name: marginLeft
Description: 
The left margin of the chart, (the margin is where the labels and title are)).
Default: 35
Name: marginRight
Description: 
The right margin of the chart, (the margin is where the labels and title are).
Default: 35
Name: marginTop
Description: 
The top margin of the chart, (the margin is where the labels and title are).
Default: 35
Name: marginBottom
Description: 
The bottom margin of the chart, (the margin is where the labels and title are).
Default: 35

Background properties

Name: backgroundGrid
Description: 
Whether the background "grid" is displayed or not.
Default: true
Name: backgroundGridColor
Description: 
The color of the background grid.
Default: #ddd
Name: backgroundGridRadialsCount
Description: 
The number of lines emanating from the center of the Radar chart outwards.
Default: null (linked to how many data points that you have)
Name: backgroundGridConcentricsCount
Description: 
The number of lines that go around the center of the Radar chart.
Default: 5
Name: backgroundGridLinewidth
Description: 
The linewidth that is used to draw the background grid.
Default: 1
Name: backgroundGridPoly
Description: 
Whether the background grid uses polygon concentric lines or circular-based ones.
Default: true

Color properties

Name: colors
Description: 
Colors to be used for the Radar chart.
Default: ['red', 'black', 'orange', 'green', '#6ff', '#ccc', 'pink', 'orange', 'cyan', 'maroon', 'olive', 'teal']
Name: filled
Description: 
Whether the Radar chart is filed or not.
Default: false
Name: filledOpacity
Description: 
The opacity of the fill in Radar charts.
Default: 0.25
Name: filledAccumulative
Description: 
If true then datasets will be stacked on top of each other.
Default: true

Labels and text properties

Name: textSize
Description: 
The size of the text.
Default: 12
Name: textFont
Description: 
The font used to render the text.
Default: Arial, Verdana, sans-serif
Name: textColor
Description: 
The color of the labels.
Default: black
Name: textItalic
Description: 
Whether the labels are italic or not.
Default: false
Name: textBold
Description: 
Whether the labels are bold or not.
Default: false
Name: textLinkColor
Description: 
The color of hyperlinked text on your chart. By default this is blue like standard links.
Default: blue
Name: textLinkFont
Description: 
The font used by hyperlinked text on your chart.
Default: null
Name: textLinkSize
Description: 
The size of hyperlinked text on your chart.
Default: null
Name: textLinkBold
Description: 
Whether hyperlinked text on your chart is bold or not.
Default: null
Name: textLinkItalic
Description: 
Whether hyperlinked text on your chart is italic or not.
Default: null
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
Name: labels
Description: 
An array of labels for the chart.
Default: []
Name: labelsSize
Description: 
The size of the text.
Default: null
Name: labelsFont
Description: 
The font used to render the text.
Default: null
Name: labelsColor
Description: 
The color of the labels.
Default: null
Name: labelsItalic
Description: 
Whether the labels are italic or not.
Default: null
Name: labelsBold
Description: 
Whether the labels are bold or not.
Default: null
Name: labelsOffset
Description: 
If you want to move the labels away from or towards the center then this is the property to use to do that.
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)

Shadow properties

Name: shadow
Description: 
Whether or not the chart has a shadow or not.
Default: false
Name: shadowOffsetx
Description: 
The horizontal offset of the shadow.
Default: 2
Name: shadowOffsety
Description: 
The vertical offset of the shadow.
Default: 2
Name: shadowBlur
Description: 
The blurring of the shadow.
Default: 2
Name: shadowColor
Description: 
The color of the shadow.
Default: rgba(0,0,0,0.25)

Title properties

Name: title
Description: 
The title of the chart.
Default: (An empty string)
Name: titleX
Description: 
The specific x-axis coordinate of the title. This can also be a string that looks like this: "+10" or "-10" in which case it's added to the calculated position.
Default: null
Name: titleY
Description: 
The specific y-axis coordinate of the title. This can also be a string that looks like this: "+10" or "-10" in which case it's added to the calculated position.
Default: null
Name: titleOffsetx
Description: 
An offset value that is added to the calculated x-axis coordinate.
Default:  0
Name: titleOffsety
Description: 
An offset value that is added to the calculated y-axis coordinate.
Default:  0
Name: titleHalign
Description: 
The horizontal alignment of the title.
Default: center
Name: titleColor
Description: 
The color of the title.
Default: null
Name: titleFont
Description: 
The font used to render the title.
Default: null
Name: titleSize
Description: 
The size of the font used to render the title.
Default: null
Name: titleBold
Description: 
Whether the title is bold or not.
Default: null
Name: titleItalic
Description: 
Whether the title is italic or not.
Default: null
Name: titleSubtitle
Description: 
The subtitle of the chart. If a subtitle is specified the title is moved up to accommodate it. As such you might need to give a larger marginTop value.
Default: (An empty string)
Name: titleSubtitleColor
Description: 
The color of the subtitle.
Default: #aaa
Name: titleSubtitleFont
Description: 
The font used to render the subtitle.
Default: null
Name: titleSubtitleSize
Description: 
The size of the font used to render the subtitle.
Default: null
Name: titleSubtitleBold
Description: 
Whether the subtitle is bold or not.
Default: null
Name: titleSubtitleItalic
Description: 
Whether the subtitle is italic or not.
Default: null

Key properties

Name: key
Description: 
An array of the labels that appear on the key.
Default: null
Name: keyColors
Description: 
An array of colors to be shown on the key. If not specified then the colors option will be used instead.
Default: null
Name: keyLabelsColor
Description: 
The color of the text in the key.
Default: null
Name: keyLabelsBold
Description: 
Whether the key text is bold or not.
Default: null
Name: keyLabelsFont
Description: 
The font to use for the key text.
Default: null
Name: keyLabelsSize
Description: 
The size to use for the key text.
Default: null
Name: ketLabelsItalic
Description: 
Whether the key text is italic or not.
Default: null
Name: keyLabelsOffsetx
Description: 
The horizontal pixel offset of the key text (just the text).
Default:  0
Name: keyLabelsOffsety
Description: 
The vertical pixel offset of the key text (just the text).
Default: -1
Name: keyOffsetx
Description: 
The horizontal pixel offset of the entire key.
Default:  0
Name: keyOffsety
Description: 
The horizontal pixel offset of the entire key.
Default:  0
Name: keyColorShape
Description: 
This controls which shape should be displayed on the key. It can be a string or an array of strings. The possible options are: circle triangle line dot rectdot
Default: rect

Tooltip properties

Name: tooltips
Description: 
An array of tooltips for the chart. This array should NOT be multidimensional - even for multiple dataset charts. You can also check the canvas tooltips documentation for more information.
Default: null
Name: tooltipsOverride
Description: 
This can be a function that handles the tooltip showing instead of the default RGraph tooltips. It should look like this:
tooltipsOverride: function (obj, opt)
{
    // Show tooltip
}
The opt is an argument that contains these items:
  • object The chart object.
  • index The index of the element (that triggered the tooltip).
  • sequentialIndex The sequential index of the element that was clicked.
  • text The text to be used as the tooltip. Remember that this may contain html (or whatever else you may have specified).
  • event The event object (either a click or mousemove event).
Default: null
Name: tooltipsEvent
Description: 
The event used for tooltips (either click or mousemove.
Default: click
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: tooltipsFormattedKeyLabels
Description: 
The labels that are used in the formatted tooltip key.
Default: [] (an empty array)
Name: tooltipsFormattedKeyColors
Description: 
The colors that are used in the formatted tooltip key. Normally these are automatically taken from the colors on the chart but can be specified differently using this property.
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: 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 in the canvas documentation, 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 (a css border, fo example) then specify an object containing those values to this property. For example:
tooltips: {
    borderLeft: 'gray 2px solid',
    borderBottom: 'gray 2px solid'
}
Default: null
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.SVG.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'
}
Default: null
Name: tooltipsPointerOffsetx
Description: 
This allows you to adjust the horizontal position of the tooltips pointer.
Default:  0
Name: tooltipsPointerOffsety
Description: 
This allows you to adjust the vertical position of the tooltips pointer.
Default:  0
Name: tooltipsCssClass
Description: 
The css class that's applied to the tooltip div.
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

Highlight properties

Name: highlightStroke
Description: 
The color of the stroke of the highlight.
Default: rgba(0,0,0,0)
Name: highlightFill
Description: 
The color of the fill of the highlight.
Default: rgba(255,255,255,0.7)
Name: highlightLinewidth
Description: 
The linewidth of the stroke of the highlight.
Default: 1

Scale properties

Name: scaleVisible
Description: 
Whether the scale is displayed or not.
Default: true
Name: scaleUnitsPre
Description: 
The units that are prepended to the numbers.
Default: (an empty string)
Name: scaleUnitsPost
Description: 
The units that are appended to the numbers.
Default: (an empty string)
Name: scaleMin
Description: 
The minimum scale value.
Default:  0
Name: scaleMax
Description: 
The maximum scale value.
Default: null
Name: scalePoint
Description: 
The character to use as the decimal point.
Default: .
Name: scaleThousand
Description: 
The character to use as the thousand separator.
Default: ,
Name: scaleRound
Description: 
Whether to round the maximum scale value up.
Default: false
Name: scaleDecimals
Description: 
The number of decimal places to display.
Default:  0
Name: scaleFormatter
Description: 
A function that handles all of the formatting of the value. The function should look like this:
function (obj, num)
{
}
Default: null
Name: scaleBold
Description: 
Whether the scale values are bold or not.
Default: null
Name: scaleItalic
Description: 
Whether the scale values are italic or not.
Default: null
Name: scaleColor
Description: 
The color of the scale labels.
Default: null
Name: scaleSize
Description: 
The size of the scale labels.
Default: null
Name: scaleFont
Description: 
The font of the scale labels.
Default: null
Name: scaleLabelsCount
Description: 
The number of scale labels.
Default: 5

Tickmark properties

Name: tickmarksStyle
Description: 
The style of tickmarks that are used. You set this to false to disable tickmarks. This can be either a string or an array of tickmark styles:
  • circle
  • filledcircle
  • rect
  • filledrect
Default: circle
Name: tickmarksLinewidth
Description: 
The linewidth used for the tickmarks.
Default: 1
Name: tickmarksSize
Description: 
The overall size of the tickmarks.
Default: 6
Name: tickmarksFill
Description: 
The fill color used for tickmarks (when in circle mode or rect mode).
Default: white

Other properties

Name: linewidth
Description: 
The linewidth of the separating lines.
Default: 1
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)

This can be used to get properties if necessary. It's normally used after the chart is drawn if you need to get parameters (if you're doing custom coding for example).

obj.set(name, value)

This can be used to set properties if necessary. It's normally used after the chart is drawn if you need to set additional parameters or change them.

obj.getRadius(value)

This can be used to get the radius for the given value.

obj.on(event, handler)

This function adds an event listener (such as beforedraw or draw) to the chart object. For example:

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

This function can be used to execute a function (immediately). It's not event-based (ie it doesn't run when something happens) - it just runs immediately - and only once. You might use it when you need to get something from the chart when it's drawn and then call the redraw function. Because this function only runs once the RGraph.SVG.redraw function would not cause a loop - which would happen if you used the draw event.

obj.exec(function (obj)
{
    // Put your code 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.

Data properties that are used on the points

The svg elements that represent the points on the Radar chart have two data attributes added to them that hold information about the indexes of the point. These are:

These can be retrieved by using standard dom methods:

element.getAttribute('data-index');

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.SVG.Radar({
    id: 'chart-container',
    data: [4,8,6,3,5,8,9],
    options: {
    }
}).on('tooltip', function (obj)
{
    console.log('The draw event has fired');
    
}).draw();