The RGraph Bar chart documentation

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Example

<script>
    // Some data that is to be shown on the bar chart. To show a stacked or grouped chart
    // each number should be an array of further numbers instead (as below).
    var data = [280,45,133];
    
    // An example of the data used by stacked and grouped charts
    // var data = [[1,5,6], [4,5,3], [7,8,9]]

    var bar = new RGraph.Bar({
        id: 'cvs',
        data: data,
        options: {
            labels: ['Richard', 'Alex', 'Nick'],
            gutterLeft: 45,
            backgroundBarcolor1: 'white',
            backgroundBarcolor2: 'white',
            backgroundGrid: true,
            colors: ['red']
        }
    }).draw();
</script>

The example file is here.

 

Properties

You can use these properties to control how the chart apears. You can set them by including them in the options section of the configuration as above.

Layout style:     
  

Background

PropertyDescriptionDefault
backgroundBarcolor1The color of the background bars, (1 of 2). white
backgroundBarcolor2The color of the background bars, (2 of 2). white
backgroundGridWhether to show the background grid or not.true
backgroundGridColorThe color of the background grid.#ddd
backgroundGridHsizeThe horizontal background grid size.40
backgroundGridVsizeThe vertical background grid size.18
backgroundGridWidthThe width that the background grid lines are. Decimals (eg 0.5) are permitted.1
backgroundGridBorderDetermines whether a border line is drawn around the grid.true
backgroundGridHlinesDetermines whether to draw the horizontal grid lines.true
backgroundGridVlinesDetermines whether to draw the vertical grid lines.true
backgroundGridAutofitInstead of specifying a pixel width/height for the background grid, you can use autofit and specify how many horizontal and vertical lines you want.true
backgroundGridAutofitNumhlinesWhen using autofit this allows you to specify how many horizontal grid lines you want.5
backgroundGridAutofitNumvlinesWhen using autofit this allows you to specify how many vertical grid lines you want.20
backgroundGridAutofitAlignIf you want to have your grid lines line up with the labels (both X and Y axes), you can set this to true and RGraph will attempt to make the grid lines line up. If you have a hmargin set then the alignment will be thrown out.false
backgroundGridDottedIf you want to have your background grid dashed then set this to true.false
backgroundGridDashedIf you want to have your background grid dotted then set this to true. This takes precedence over dashed lines.false
backgroundHbarsAn array of information stipulating horizontal coloured bars. You can use these to indicate limits. Eg: myBar.set('hbars', [[75, 10, 'yellow'], [85, 15, 'red']]); This would give you two bars, one red and a lower yellow bar. The units correspond to your scale, and are the starting point and the height.null
backgroundImageIf you want to specify a background image to use on your chart, specify it with this property. If you use effects with a background image on your chart it may make the effect flicker. Using a background image with the ondraw event may mean that the event fires twice. There is a property that you can check though that is set when the image has loaded: obj.__rgraph_background_image_loaded__ Simply check this flag in your ondraw event. If it's true then the background image has loaded.null
backgroundImageStretchBy default your background image is stretched (if necessary) to cover the whole chart area (gutters not included). If this is not what you want then set this property to false.true
backgroundImageXThe X position of the image. The coordinates are the top left corner of the image.null
backgroundImageYThe Y position of the image. The coordinates are the top left corner of the image.null
backgroundImageWThe width of the image. If you have a large canvas with many charts - you may need to specify this.null
backgroundImageHThe height of the image. If you have a large canvas with many charts - you may need to specify this.null
backgroundImageAlignInstead of specifying the coordinates of the image, you can instead simply align it top, bottom, left or right. Examples are:
  • top left
  • bottom right
  • bottom
  • right
null
backgroundImageAlphaThe alpha value (the opacity) of the image.1
backgroundColorIf you want to have a single background color for your chart you can use this. It doesn't cover the gutters. If you want that then you can simply apply a CSS background color to the canvas tag.null

Axes properties

PropertyDescriptionDefault
noaxesTurns off the drawing of the axesfalse (the axes ARE drawn)
noxaxisWhether the X axis is drawnfalse (the X axis IS drawn)
noyaxisWhether the Y axis is drawnfalse (the Y axis IS drawn)
noendxtickWhen you're combining the Bar and Line charts, you may want to use this property to stop the end X tick from being drawn.false (the end tick IS drawn)
numxticksThis controls the number of X tickmarks on the X axis.null
numyticksThe number of Y tickmarks.10
axisColorThe color of the axes.black
axisLinewidthThe linewidth of the axes.1

Colors

PropertyDescriptionDefault
strokestyleThe color of the outline of the bars.rgba(0,0,0,0)
colorsAn array of the colors of the bars.An array - ['rgb(0,0,255)', '#0f0', '#00f', '#ff0', '#0ff', '#0f0']
colorsSequentialIf true, for regular bar charts, (not stacked or grouped), the colors that you specify will be used in a sequential fashion.false
colorsReverseIf true, for stacked bar charts only, the colors that you specify will be used in a reverse order to what they are normally.false

Margins

PropertyDescriptionDefault
hmarginThe horizontal margin (in pixels) of the chart. The horizontal margin is on the inside of the axes.5
hmarginGroupedIn a grouped bar chart this is the margin between bars that are on the same group. You can see examples of the hmargins in the RGraph demos.1
gutterLeftThe left gutter of the chart, (the gutter is where the labels and title are)).25
gutterRightThe right gutter of the chart, (the gutter is where the labels and title are).25
gutterTopThe top gutter of the chart, (the gutter is where the labels and title are).25
gutterBottomThe bottom gutter of the chart, (the gutter is where the labels and title are).25

Labels and text

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 gutters 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
textColorThe color of the labels.black
textSizeThe size (in points) of the labels.10
textAngleThe angle of the horizontal text labels (at the bottom of the chart). This can be from 90 to -90 degrees0 (Horizontal)
textFontThe font used to render the text.Arial
labelsAn array of the labels to be used on the chart.An empty array
labelsBoldWhether the labels are bold or notfalse
labelsColorThe color of the labelsnull (same as textColor)
labelsAboveIf true, values will be shown above the bars. For regular and stacked bar charts units are included, whereas for grouped bar charts they're not (usually there isn't enough space for them).false
labelsAboveDecimalsThis stipulates how many decimals are used in the above bar labels.0
labelsAboveUnitsPreThe units to put on the above labels. These are positioned BEFORE the number0
labelsAboveUnitsPostThe units to put on the above labels. These are positioned AFTER the number0
labelsAboveSizeThe font size of the above bar labels. Useful if you only have a few bars.null
labelsAboveBackgroundThe background-color of the labels above the barsrgba(0,0,0,0)
labelsAboveColorThe color of the labels above the barsnull(defaults to text.color setting)
labelsAboveOffsetThe distance of the labels above the bars (in pixels)4
labelsAboveAngleYou can use this to angle the text shown above the bars. It can be anything from -90 to 90 (degrees).null
labelsAboveSpecificIf instead of the values you want to show arbitrary text - you can with this. It should be an arry of the labels to be shown.null
labelsIngraphAn array of labels for the chart which are drawn "inside" the chart. If you have 5 data points then this should have a corresponding number of elements, though there is a shorthand available.null
labelsOffsetxThis allows you finer grained control in the horizontal direction over the X label positioning if you need it.0
labelsOffsetyThis allows you finer grained control in the vertical direction over the X label positioning if you need it.0
ylabelsCan be true or false and determines whether the chart has Y axis labels.true
ylabelsCountA value that controls how many Y labels there are. This value could formerly be either 1/3/5/10 however now it can be any number.5
ylabelsSpecificYou can use this option to give your own Y labels (eg ['Low', 'Medium', 'High']. Note: Since March 2013 you may now need to add an extra (optionally) empty element to the array of labels to achieve your desired result.null
ylabelsOffsetxThis allows you finer grained control in the horizontal direction over the Y label positioning if you need it.0
ylabelsOffsetyThis allows you finer grained control in the vertical direction over the Y label positioning if you need it.0

Titles

PropertyDescriptionDefault
titleThe title of the chart, if any.null
titleFontThe font that the title is rendered in. If not specified the text.font setting is used (usually Arial)null
titleSizeThe size of the title. If not specified the size is usually 2pt bigger than the text.size 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 thisnull
titleYTo give the exact Y coordinate for the title - use thisnull
titleXaxisThis allows to specify a title for the X axis.none
titleXaxisSizeThis allows you to specify a size for the X axis title.null
titleXaxisFontThis allows to specify a font for the X axis title.null
titleXaxisBoldThis controls whether the X axis title is bold or not.true
titleXaxisColorThis controls the color of the X axis title.black
titleXaxisXBy giving this you can specifically set the X position of the X axis titlenull
titleXaxisYBy giving this you can specifically set the Y position of the X axis titlenull
titleYaxisThis allows to specify a title for the Y axis.none
titleYaxisSizeThis allows you to specify a size for the Y axis title.null
titleYaxisFontThis allows to specify a font for the Y axis title.null
titleYaxisBoldThis controls whether the Y axis title is bold or not.true
titleYaxisColorThis controls what color the Y axis is.black
titleXaxisPosThis is multiplied with the gutter to give the position of the X axis title.0.25
titleYaxisPosThis is multiplied with the gutter to give the position of the Y axis title.0.25
titleYaxisXBy giving this you can specifically set the X position of the Y axis titlenull
titleYaxisYBy giving this you can specifically set the Y position of the Y axis titlenull

Shadow

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

Scale

PropertyDescriptionDefault
scaleFormatterTo allow thoroughly custom formats of numbers in the scale, you can use this option to specify a function that is used by RGraph to format numbers. This function should handle ALL of the formatting. Eg:

function myFormatter(obj, num)
{
    return num + 'F'; // An example of formatting
}
myGraph.set('scale.formatter', myFormatter);
null
scaleRoundWhether to round the scale up. eg A maximum value of 59 results in scale to 100.false
scaleDecimalsThe number of decimal places to display for the Y scale.0
scalePointThe character used as the decimal point..
scaleThousandThe character used as the thousand separator,
scaleZerostartWhether the scale starts at zero or not.true
unitsPreThe units that the Y axis is measured in. This string is displayed BEFORE the actual number, allowing you to specify values such as "$50".none
unitsPostThe units that the Y axis is measured in. This string is displayed AFTER the actual number, allowing you to specify values such as "50ms".none
ymaxThe optional maximum Y scale value. If not specified then it will be calculated.null (It's calculated)
yminThe optional minimum Y scale value. If not specified then it will be 0.0

Key

The key properties are documented on the key documentation page.

Interactive features

PropertyDescriptionDefault
contextmenuAn array of context menu items. More information on context menus is here.[] (An empty array)
tooltipsA numerically indexed array of tooltips that are shown when a bar is clicked. These can contain HTML.null
tooltipsEffectThe effect used for showing tooltips. Can be either fade or none.fade
tooltipsEventThis is the event that triggers the tooltips. It can be either onclick or onmousemove.onclick
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 pagenull
tooltipsHighlightSet this to false if you don't want your charts to be highlighted.true
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 tooltip DO NOT get hidden.false
tooltipsHotspotXonlyIf set to true the hotspot for the tooltips will ignore the height of the bar and extend from top gutter down to the bottom gutter. This can be useful when you have zero value bars but still want to see the tooltips.false
crosshairsIf true, you will get a crosshair centering on the current mouse position.false
crosshairsLinewidthThis controls the linewidth of the crosshairs.1
crosshairsColorThe color of the crosshairs.#333
crosshairsHlinesThis determines whether the horizontal crosshair is shown.true
crosshairsVlinesThis determines whether the vertical crosshair is shown.true
annotatableWhether annotations are enabled for the chart (ie you can draw on the chart interactively.false
annotateColorIf you do not allow the use of the palette, then this will be the only colour allowed for annotations.black
annotateLinewidthThis is the line width 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
resizeHandleBackgroundWith 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
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
adjustableDefaulting to false, this determines whether your bar chart will be adjustable.false
adjustableOnlyThis should be an array of values that determine whether a Bar is adjustable or not. A truthy value for when it is, a falsey value for when its not.null

Zoom

PropertyDescriptionDefault
zoomFactorThis is the factor that the chart will be zoomed by (bigger values means more zoom)1.5
zoomFadeInWhether the zoomed canvas fades in or not. This also can be used to control the fade in for the zoom in thumbnail mode.true
zoomFadeOutWhether the zoomed canvas fades out or not. This also can be used to control the fade in for the zoom in thumbnail mode.true
zoomHdirThe horizontal direction of the zoom. Possible values are: left, center, rightright
zoomVdirThe vertical direction of the zoom. Possible values are: up, center, downdown
zoomDelayThe delay (in milliseconds) between frames.50
zoomFramesThe number of frames in the zoom animation.10
zoomShadowWhether or not the zoomed canvas has a shadow or not.true

Events

PropertyDescriptionDefault
eventsClickIf you want to add your own onclick function you can do so by assigning it to this property. See here for details.null
eventsMousemoveIf you want to add your own onmousemove function you can do so by assigning it to this property. See here for details.null
eventsMouseoverIf you want to add your own onmouseover function you can do so by assigning it to this property. See here for details.null
eventsMouseoutIf you want to add your own onmouseout function you can do so by assigning it to this property. See here for details.null

Miscellaneous

PropertyDescriptionDefault
highlightStyleBy 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. Its passed the shape object as an argument.null
highlightStrokeIf you use tooltips, this controls the colour of the highlight stroke.black
highlightFillIf you use tooltips, this controls the colour of the highlight fill.rgba(255,255,255,0.5)
variantThis stipulates whether you want a regular bar chart or a 3D chart. In August 2015 the 3D variant has much improved perspective. Possible values are:
  • bar
  • 3d
bar
variantThreedOffsetxThis determines the size of the offset in the X direction10
variantThreedOffsetyThis determines the size of the offset in the Y direction5
variantThreedXaxisThis allows you to turn on/off the threed X axistrue
variantThreedYaxisThis allows you to turn on/off the threed Y axistrue
xaxisposThe position of the X axis. This can be bottom, center or top.bottom
yaxisposSpecifies the Y axis position. Can be left or rightleft
groupingHow the bars are grouped, and it should be one of: grouped or stackedgrouped
bevelIf true the bars will be given a 3D bevelled appearance.false
cleartoThis is used in animations and effects as the default color to use when clearing the canvas.null
errorbarsThis should be an array of errorbar information or it can simply be a number instead (see below).false
errorbarsLinewidthThis is the linewidth of the errorbars.1
errorbarsColorThis is the color of the errorbars. You can also override the color in the errorbar array.black
errorbarsCappedThis dictates whether the errorbars have caps on their ends or not.true
errorbarsCappedWidthThis is the width of the caps (in total) on the end of the errorbar.14
combinedchartEffectSet this to the name of an effect (eg grow ) and the CombinedChart object will use that effect to draw the chart instead of the regular draw() functionnull
combinedchartEffectOptionsThis should be a STRING that contains a JavaScript object of options for the effect function like this:
combinedchartEffectOptions: '{frames: 300}'
It has to be a string because of a quirk of the option parsing system.
null
combinedchartEffectCallbackA function that runs when this objects effect has conpleted.null

 

Methods

 

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

 

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

 

obj.getShape(event)

This method makes it easier to get hold of which bar has been clicked on, or hovered over. It returns an array of:

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

An example usage is:
<canvas id="cvs" width="600" height="250">[No canvas support]</canvas>

<script src="RGraph.common.core.js"></script>
<script src="RGraph.bar.js"></script>

<script>
    bar = new RGraph.Bar({
        id: 'cvs',
        data: [1.2, 1.3, 1.4, 1.5,6,1.9,2,2.1,2.5],
        options: {
            labels: ['John', 'Barry', 'Rich', 'Craig', 'Tom', 'Frank', 'Helen', 'Joyce', 'Fred']
        }
    }).draw();
    
    bar.canvas.onclick = function (e)
    {
        RGraph.Redraw();
    
        var ca  = e.target;
        var co  = ca.getContext('2d');
        var obj = ca.__object__;
        var coords  = obj.getShape(e);
        
        if (coords) {
            var top    = coords[1];
            var left   = coords[2];
            var width  = coords[3];
            var height = coords[4];
            
            co.strokeStyle = 'black';
            co.fillStyle = 'rgba(255,255,255,0.5)';
            co.strokeRect(top, left, width, height);
            co.fillRect(top, left, width, height);
        }
    }
</script>

 

obj.getShapeByX(event)

This method is similar to the above, but only uses the X coordinate to get the relevant bar.

 

obj.getValue(mixed)

This method can be used to get the value at a particular point or at the mouse coordinates, based on the scale that is in use. Not simply the coordinates of the mouse. The argument can either be an event object (for use in event listener functions) OR a two element array consisting of the X and Y coordinates (ie when you're not necessarily in an event listener). It returns null if the mouse or coordinates are in the gutter areas. An example:

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

 

obj.getYCoord(value)

This method can be used to get an appropriate Y coord for a value when you're doing custom drawing on the chart. It returns null if the value is out of range.

 

obj.on(event, func)

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 you wish to attach to and the second is the handler function. For example:

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

 

The exec option and method

The exec function is documented here.

 

Errorbars

Errorbars can allow you show an upper and lower range for a particular bar like this example page here shows. You can specify errorbars like this:

var bar = new RGraph.Bar({
    id: 'cvs',
    data: [12,18,10,9,6,20,18],
    options: {
        labels: ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'],
        shadow: false,
        colors: ['red'],
        strokestyle: 'rgba(0,0,0,0)',
        errorbars: [ [5,3], [2,6], [5,15,'blue',5,45] ],
        errorbarsLinewidth: 2,   // The default linewidth
        errorbarsColor: 'gray',  // The default color
        errorbarsCapped: true,   // Whether the ends of the errorbar have terminating lines
        errorbarsCappedWidth: 14 // The default width of the caps
    }                
}).draw();

This would give you three errorbars and the elements of each errorbar array are (each one is optional):

 

Note about the data_arr array

Sometimes you may wish to view your data as one big array, instead of one array per dataset. In this case the obj.data_arr is available. This is one long array containing all of the individual data points.

 

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)
    {
        // ...
    }

    var obj = new RGraph.Bar({
        id: 'cvs',
        data: [3,4,7,5,6,9,8],
        options: {
            gutterLeft: 35,
            hmargin: 60
        }
    }).wave({frames: 60}, myCallback);
    // .grow({frames: 60}, myCallback);
</script>