Using Group Markers in a Chart

By default, charts render a marker for each data point in a series. This is useful for interactivity and custom styling but when there are many data points, performance can suffer. With a ComboSeries, you can set showMarkers to false and interactionType to planar for larger data sets, but this is of no help with a histogram. Additionally, you may still prefer visual markers for each data point in your chart. In this example, we'll take a large data set and display it on a ComboSeries with groupMarkers.

CSS

#mychart {
    margin:10px 10px 10px 10px;
    width:90%;
    max-width: 800px;
    height:400px;
}

HTML

<div id="mychart"></div>

JavaScript

//set canvas as the defaultGraphicEngine
YUI({
    defaultGraphicEngine: "canvas"
}).use('charts', function (Y)
{
    var myDataValues = getData();

    //style the series
    var myseries = [
        {
            styles: {
                line: {
                    weight: 1
                }
            }
        },
        {
            styles: {
                line: {
                    weight: 1
                }
            }
        }

    ];

    //instantiate chart with interactionType of planar and groupMarkers set to true
    var mychart = new Y.Chart({
            interactionType:"planar",
            groupMarkers:true,
            dataProvider:myDataValues,
            categoryType:"time",
            categoryKey:"date",
            render:"#mychart",
            seriesCollection: myseries,
        });

});