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	<title>Flot Examples: Real-time updates</title>

	<link href="../examples.css" rel="stylesheet" type="text/css">

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	<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>

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<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>



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		Copyright &copy; 2007 - 2014 IOLA and Ole Laursen

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