<!DOCTYPE html PUBLIC β€œ-//W3C//DTD HTML 4.01//EN” β€œwww.w3.org/TR/html4/strict.dtd”> <html> <head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Flot Examples: Real-time updates</title>
<link href="../examples.css" rel="stylesheet" type="text/css">
<!--[if lte IE 8]><script language="javascript" type="text/javascript" src="../../excanvas.min.js"></script><![endif]-->
<script language="javascript" type="text/javascript" src="../../jquery.js"></script>
<script language="javascript" type="text/javascript" src="../../jquery.flot.js"></script>
<script type="text/javascript">

$(function() {

        // We use an inline data source in the example, usually data would
        // be fetched from a server

        var data = [],
                totalPoints = 300;

        function getRandomData() {

                if (data.length > 0)
                        data = data.slice(1);

                // Do a random walk

                while (data.length < totalPoints) {

                        var prev = data.length > 0 ? data[data.length - 1] : 50,
                                y = prev + Math.random() * 10 - 5;

                        if (y < 0) {
                                y = 0;
                        } else if (y > 100) {
                                y = 100;
                        }

                        data.push(y);
                }

                // Zip the generated y values with the x values

                var res = [];
                for (var i = 0; i < data.length; ++i) {
                        res.push([i, data[i]])
                }

                return res;
        }

        // Set up the control widget

        var updateInterval = 30;
        $("#updateInterval").val(updateInterval).change(function () {
                var v = $(this).val();
                if (v && !isNaN(+v)) {
                        updateInterval = +v;
                        if (updateInterval < 1) {
                                updateInterval = 1;
                        } else if (updateInterval > 2000) {
                                updateInterval = 2000;
                        }
                        $(this).val("" + updateInterval);
                }
        });

        var plot = $.plot("#placeholder", [ getRandomData() ], {
                series: {
                        shadowSize: 0   // Drawing is faster without shadows
                },
                yaxis: {
                        min: 0,
                        max: 100
                },
                xaxis: {
                        show: false
                }
        });

        function update() {

                plot.setData([getRandomData()]);

                // Since the axes don't change, we don't need to call plot.setupGrid()

                plot.draw();
                setTimeout(update, updateInterval);
        }

        update();

        // Add the Flot version string to the footer

        $("#footer").prepend("Flot " + $.plot.version + " &ndash; ");
});

</script>

</head> <body>

<div id="header">
        <h2>Real-time updates</h2>
</div>

<div id="content">

        <div class="demo-container">
                <div id="placeholder" class="demo-placeholder"></div>
        </div>

        <p>You can update a chart periodically to get a real-time effect by using a timer to insert the new data in the plot and redraw it.</p>

        <p>Time between updates: <input id="updateInterval" type="text" value="" style="text-align: right; width:5em"> milliseconds</p>

</div>

<div id="footer">
        Copyright &copy; 2007 - 2014 IOLA and Ole Laursen
</div>

</body> </html>