Line chart API reference

• Example
• Using errorbars on the Line chart
• The coordinates properties
• Properties
• Methods
• Data properties that are used on the points
• Events
• Effects

Example

<script>
    // Some data that is to be shown on the Bar chart. For multiple
    // lines it can also be an array of arrays
    // data = [280,45,133,152,278,221,56];
    
    // An example of the data used by multiple dataset Line charts
    data = [
        [1,9,8,4,6,5,3],
        [1,6,5,3,3,8,6]
    ];

    new RGraph.SVG.Line({
        id: 'chart-container',
        data: data,
        options: {
            backgroundGridVlines: false,
            backgroundGridBorder: false,
            xaxis: false,
            yaxis: false,
            xaxisLabels: ['Mon','Tue','Wed','Thu','Fri','Sat','Sun'],
            days: ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'],
            tooltips: '<b>%{property:days[%{index}]}: %{value}%</b>',
            tooltipsCss: {
                backgroundColor: '#333',
                fontWeight: 'bold',
                fontSize: '14pt',
                opacity: 0.85
            },
            linewidth: 3,
            marginTop: 45,
            marginLeft: 25,
            spline: true,
            filled: true,
            filledOpacity: 0.5,
            filledAccumulative: true,
            linewidth: 0,
            title: 'A Line chart showing dual datasets',
            titleSubtitle: 'The datasets don\'t show anything particularly interesting'
        }
    }).draw();
</script>

Using errorbars on the Line chart

One of the features that the Line chart has is the ability to display errorbars. This is demonstrated by the chart that's shown here. The errorbars property should be an array of objects but each element can be the following:

• null
• undefined
• A number
• An object with just the max property set
• An object with just the min property set
• An object with both the min and max properties set

An example of some code for a chart that has errorbars is shown below:

<script>
    new RGraph.SVG.Line({
        id: 'cc',
        data: [8,4,8,6,3,5,8],
        options: {
            marginLeft: 50,
            title: 'A Line chart with errorbars',
            textSize: 14,
            xaxisLabels: ['Mon','Tue','Wed','Thu','Fri','Sat','Sun'],
            errorbars: null,
            yaxis: false,
            backgroundGridBorder: false,
            backgroundGridVlines: false,
            spline: true,
            shadow: true,
            errorbars: [
                1,
                null,
                , // Undefined
                0,
                {min:1, max: 5},
                {min: 1},
                {max: 1}
            ]
        }
    }).draw();
</script>

The coordinates properties

The coordinates for the points on the Line chart are held in the following arrays:

• obj.coords
  All of the coordinates - that are simply appended to this array as each point is drawn. Each element of the array is an object which consists of x, y, index, object, value and path properties. The object is a reference to the RGraph object and the path is an array that contains svg path commands.
  
  
• obj.coords2
  Again, this is all of the coordinates - but arranged slightly differently. This array contains 1 array per line that is drawn on the chart. Each of these arrays contains the points for that line arranged as one object per point. Like the obj.coords array, each object contains these properties: x, y, index, object, path, value.
  
  
• obj.coordsSpline
  This is an array of spline coordinates if spline mode is enabled. It contains many more coordinates than the above two to make the curvy line. It's arranged by line index and then each of these arrays contains objects that are made up of x, y and object 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.

• Background properties
• Margin properties
• Color properties
• Fill properties
• X-axis properties
• Y-axis properties
• Other text properties
• Tooltip properties
• Tickmark properties
• Shadow properties
• Title properties
• Key properties
• Error bar properties
• Trend line properties
• Null value properties
• Other properties

filledClick: function (e, obj, index)
{
    // e:     The event object
    // obj:   The chart object
    // index: The index of the line that was clicked
},

yaxisFormatter: function (obj, num)
{
}

tooltipsOverride: function (obj, opt)
{
    // Show tooltip
}

tooltipsFormattedKeyColorsCss : {
    border: "1px solid #ddd";
}

tooltipsFormattedListItems: [
    ['Bill','Jerry','Berty'], // First tooltip
    ['Gill','Carrie','Lucy'], // Second tooltip
    ['Pob','Nobby','Hilda']   // Third tooltip
]

.RGraph_tooltip ul#rgraph_formatted_tooltips_list li {
    text-align: left;
    color: yellow;
}

tooltips: {
    borderLeft: 'gray 2px solid',
    borderBottom: 'gray 2px solid'
}

tooltipsCss: {
    fontFamily: 'Verdana',
    fontSize: '20pt'
}

obj.set('horizontalLines', [
    {
        value: 'average',
        dashed: true,
        labelPosition:'left bottom'
    },
    {
        value: 10.48,
        label:'Value (%{value})',
        labelValueDecimals: 2,
        labelValueThousand: ',',
        labelValuePoint:'.',
        labelValueUnitsPre:'',
        labelValueUnitsPost:''
        //labelValueFormatter: function (opt)
        //{
        //    return opt.number;
        //}
    }
]);

Methods

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).

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.

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

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
});

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
});

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 circle or rect elements that represent the tickmark hotspots on the Line chart have various data attributes added to them that hold various bits of information. These are:

• data-index
• data-dataset

These can be retrieved by using standard dom methods:

hotspot.getAttribute('data-index');

Note that for stacked and grouped charts the group can be retrieved by doing this:

sequentialIndex = obj.coords[0].element.getAttribute('data-sequential-index');
indexes         = RGraph.SVG.sequentailIndexToGrouped(sequentialIndex, obj.data);

Events

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

• beforedraw This event fires at the start of the draw method before anything has been done.
• draw This event fires at the end of the draw function.
• firstdraw This event fires at the end of the draw function - but only the first time and so it fires only once after the first draw call.
• beforetooltip This event fires at the start of the tooltip showing process.
• tooltip This event fires after a tooltip has been shown.

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

Effects

• The trace effect (demo available in the download archive)

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

    var obj = new RGraph.SVG.Line({
        id: 'mySVG',
        data: [3,4,7,5,6,9,8],
        options: {
        }
    }).trace({frames: 60}, myCallback);
</script>