# A black and purple combined chart

This demo is an example of a combined Bar and Line. In this case, the Line is a `spline` but it doesn't have to be. In fact there's a button beneath the chart that you can use to toggle whether it's a `spline` (curvy) or a regular angular Line. All this button does is toggle the `spline` setting and then redraw the `canvas`.

In RGraph, combining a Bar chart and a Line chart is made easy by the `CombinedChart` class. You can see this being used in the code below. It simply takes the Bar and the Line objects and sets the correct settings on them and then draws the chart. But normally you would want only one set of labels (ie the Bar or the Line) drawn, however here the Bar charts labels are on one side and the Line chart labels are on the other. So after the combo class has been drawn, the `Y-axis` labels are turned back on for the Line chart object and everything is redrawn. You can see how this is done in the code below.

The `CombinedChart` class is freely usable by you in a very similar way to the other RGraph classes. It's created in the same way and you pass it an array of objects - which usually is a combination of Bar and Line objects. You can give it more types if you want.

Apart from this, the chart has "larger than the default" text and the Bar uses a gradient for the fill color: `Gradient(#A18AC5:#D1AAF5)`

The `responsive` function reduces the size of the chart, the size of the text on the chart and the margins. The function is added to both the Bar and the Line chart and the Line chart version also reduces its `linewidth`.

This goes in the documents header:

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

Put this where you want the chart to show up:

    <div style="float: right; display: inline-block; margin: 25px">
        <canvas id="cvs" width="750" height="250" style="background-color: #555; border: 5px solid black; border-radius: 7px; box-shadow: 2px 2px 3px gray">[No canvas support]</canvas><br />
        <button style="border-radius: 5px; font-size: 20px; margin: 10px; padding: 7px" onclick="line.set('spline', !line.get('spline')); RGraph.redraw()">Toggle spline</button>
    </div>

This is the code that generates the chart - it should be placed AFTER the `canvas` tag(s):