Bar chart API reference

Summary: Documentation about the Bar chart including information about all of the options that are available to you. The Bar chart is a very commonly used type of chart and is very versatile. As such there are lots of Bar chart demos available in the download that demonstrate what you can do with it.

• Example
• Properties
• Methods
• Custom RGraph events that are available
• Errorbars
• Note about the data_arr array
• Bar chart effects

Example

<script>
    data   = [[3,5,6],[8,4,5],[4,9,6]];
    labels = ['Richard', 'Alex', 'Nick'];
    
    new RGraph.Bar({
        id: 'cvs',
        data: data,
        options: {
            xaxisTickmarksCount: 0,
            xaxisLinewidth: 5,
            backgroundGridVlines: false,
            backgroundGridBorder: false,
            yaxis: false,
            colors:[
                'Gradient(#faa:red)',
                'Gradient(#afa:green)',
                'Gradient(#aaf:blue)'
            ],
            textSize: 24,
            xaxisLabels: labels,
            marginLeft: 45,
            backgroundGrid: true,
            marginInner: 50,
            tooltips: '<b>Results</b><br />%{key}',
            tooltipsFormattedKeyLabels: ['06:00','12:00','18:00'],
            tooltipsFormattedKeyColors:['red','green','blue'],
            tooltipsFormattedUnitsPost: '%',
            tooltipsCss: {
                fontSize: '16pt',
                backgroundColor: 'black',
                color:'white',
                textAlign: 'left'
            }
        }
    }).wave();
</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.

• Background properties
• X axis properties
• Y axis properties
• Color properties
• Margin properties
• Other label properties
• Title properties
• Shadow properties
• Key properties
• Interactive features properties
• Miscellaneous properties

Background properties

X axis properties

Y axis properties

function myFormatter(opt)
{
    var num = Number(opt.number) * 5;

    return String(num)
}
obj.set('yaxisScaleFormatter', myFormatter);

function myFormatter(opt)
{
    var num = Number(opt.number) * 5;

    return String(num)
}
obj.set('yaxisScaleFormatter', myFormatter);

Color properties

Margin properties

Other label properties

<div style="margin-left: 50px; display: inline-block">
    <canvas id="cvs" width="650" height="250"></canvas>
</div>

<div style="margin-left: 50px; display: inline-block">
    <canvas id="cvs" width="650" height="250"></canvas>
</div>

Title properties

Shadow properties

Key properties

Interactive features properties

tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt',
    backgroundColor: 'black',
    color: 'white'
}

tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt',
    backgroundColor: 'black',
    color: 'white'
}

Miscellaneous properties

combinedEffectOptions: '{frames: 300}'

combinedEffectOptions: '{frames: 300}'

Methods

<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,
                width  = shape.width,
                height = shape.height;
            
            obj.path(
                'b r % % % % s black f red',
                x, y, width, height
            );
        }
    }
</script>

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

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 in an event listener function). It returns null if the mouse or coordinates are in the margin areas. An example:

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

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

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 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.

• click
• mousemove
• mouseover
• mouseout

There's more documentation about events available here: Summary of events documentation

<script>
    bar = new RGraph.Bar({
        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>

Errorbars

Errorbars can allow you to show an upper and lower range for a particular bar like the bar-errorbars.html example page shows in the download archive. You can specify errorbars like this:

bar = new RGraph.Bar({
    id: 'cvs',
    data: [12,18,10,9,6,20,18],
    options: {
        xaxisLabels: ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'],
        shadow: false,
        colors: ['red'],
        colorsStroke: '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):

• The upper extent of the errorbar
• The lower extent of the errorbar
• The color of this errorbar
• The linewidth of this errorbar
• The (total) width of the cap at the end of this errorbar

Note about the data_arr array

Animation effects

• Wave effect (effects-bar-wave.html in the download archive)
• Grow effect (effects-bar-grow.html in the download archive)
• ColorWave effect (effects-bar-color-wave.html in the download archive)

<script>
    /**
    * The optional callback function that's called when the effect is complete
    */
    function myCallback (obj)
    {
        // ...
    }

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