/home/mip/public_html/template/AdminLTE/plugins/RGraph/demos/line-dynamic-updates.html
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<html>
<head>
<link rel="stylesheet" href="demos.css" type="text/css" media="screen" />
<script src="../libraries/RGraph.common.core.js" ></script>
<script src="../libraries/RGraph.line.js" ></script>
<title>A dynamically updating Line chart</title>
<meta name="robots" content="noindex,nofollow" />
<meta name="description" content="A dynamically updating Line chart. The data here is simply generated randomly but could just as easily be retrieved from a server via AJAX (for example)." />
</head>
<body>
<h1>A dynamically updating Line chart</h1>
<p>
This chart updates itself 20 times a second.New values are appended to the data that's displayed and old values are removed
from the data. Careful use is made of local variables - so that the updates are done smoothly.
</p>
<p>
Setting the ymax to 250 means the scale stays the same - but you can also have a dynamic scale that
changes to accommodate the values on the chart.
</p>
<div style="text-align:center; font-weight: bold; font-size: 14pt; width: 600px">
Bandwidth used (Mb/s)<br />
<canvas id="cvs" width="600" height="250">[No canvas support]</canvas><br />
<span style="font-size: 12pt; font-weight: normal">
Last 60 seconds
</span>
</div>
<button id="toggleButton">Toggle ymax to 250</button>
<script>
window.onload = function ()
{
var RG = RGraph;
var ma = Math;
var canvas = document.getElementById("cvs");
var obj = null;
var data = [];
var l = 0; // The letter 'L' - NOT a one
var numvalues = 1200;
var updates = 0;
// Pre-pad the arrays with null values
for (var i=0; i<numvalues; ++i) {
data.push(null);
}
function drawGraph ()
{
RG.Clear(canvas);
if (!obj) {
obj = new RG.Line({
id: 'cvs',
data: [],
options: {
colors: ['black'],
linewidth: 0.75,
yaxispos: 'right',
shadow: false,
tickmarks: null,
gutterTop: 10,
gutterBottom: 15,
gutterRight: 40,
backgroundGridVlines: false,
numyticks: 5,
numxticks: 0,
ylabelsCount: 5,
scaleZerostart: true,
textAccessible: true,
noxaxis:true
}
})
}
// Add some data to the data arrays
var len = data.length;
var lastvalue = RG.isNull(data[len - 1]) ? 26 : data[len - 1];
var random_value = RG.random(lastvalue - 2,lastvalue + 2);
random_value = ma.max(random_value, 0);
random_value = ma.min(random_value, 250);
data.push(random_value);
if (data.length > numvalues) {
data = RG.arrayShift(data);
}
if (RG.ISIE8) {
alert('[MSIE] Sorry, Internet Explorer 8 is not fast enough to support dynamic charts');
} else {
obj.original_data[0] = data;
obj.draw();
setTimeout(drawGraph, 16.666);
}
updates++;
if (updates % 100 === 0) {
console.log(updates);
}
}
drawGraph();
/**
* Add the toggle buttons onclick function
*/
document.getElementById("toggleButton").onclick = function (e)
{
if (obj.get('ymax')) {
obj.set('ymax', null)
} else {
obj.set('ymax', 250)
}
}
};
</script>
<p></p>
This goes in the documents header:
<pre class="code">
<script src="RGraph.common.core.js"></script>
<script src="RGraph.line.js"></script>
</pre>
Put this where you want the chart to show up:
<pre class="code">
<div style="text-align:center; font-weight: bold; font-size: 14pt; width: 600px">
Bandwidth used (Mb/s)<br />
<canvas id="cvs" width="600" height="250">[No canvas support]</canvas><br />
<span style="font-size: 12pt; font-weight: normal">
Last 60 seconds
</span>
</div>
<button id="toggleButton">Toggle ymax to 250</button>
</pre>
This is the code that generates the chart:
<pre class="code">
<script>
window.onload = function ()
{
var RG = RGraph;
var ma = Math;
var canvas = document.getElementById("cvs");
var obj = null;
var data = [];
var l = 0; // The letter 'L' - NOT a one
var numvalues = 1200;
var updates = 0;
// Pre-pad the arrays with null values
for (var i=0; i<numvalues; ++i) {
data.push(null);
}
function drawGraph ()
{
RG.Clear(canvas);
if (!obj) {
obj = new RG.Line({
id: 'cvs',
data: [],
options: {
colors: ['black'],
linewidth: 0.75,
yaxispos: 'right',
shadow: false,
tickmarks: null,
gutterTop: 10,
gutterBottom: 15,
gutterRight: 40,
backgroundGridVlines: false,
numyticks: 5,
numxticks: 0,
ylabelsCount: 5,
textAccessible: true,
scaleZerostart: true,
noxaxis: true
}
})
}
// Add some data to the data arrays
var len = data.length;
var lastvalue = RG.isNull(data[len - 1]) ? 26 : data[len - 1];
var random_value = RG.random(lastvalue - 2,lastvalue + 2);
random_value = ma.max(random_value, 0);
random_value = ma.min(random_value, 250);
data.push(random_value);
if (data.length > numvalues) {
data = RG.arrayShift(data);
}
if (RG.ISIE8) {
alert('[MSIE] Sorry, Internet Explorer 8 is not fast enough to support dynamic charts');
} else {
obj.original_data[0] = data;
obj.draw();
setTimeout(drawGraph, 16.666);
}
updates++;
if (updates % 100 === 0) {
console.log(updates);
}
}
drawGraph();
/**
* Add the toggle buttons onclick function
*/
document.getElementById("toggleButton").onclick = function (e)
{
if (obj.get('ymax')) {
obj.set('ymax', null)
} else {
obj.set('ymax', 250)
}
}
};
</script>
</pre>
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