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- <!DOCTYPE HTML>
- <html>
- <head>
- <title>Graph2d | Interpolation</title>
- <link href="../../dist/vis.css" rel="stylesheet" type="text/css" />
- <style type="text/css">
- body, html {
- font-family: sans-serif;
- }
- </style>
-
- <script src="../../dist/vis.js"></script>
-
- <script>(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)})(window,document,'script','//www.google-analytics.com/analytics.js','ga');ga('create', 'UA-61231638-1', 'auto');ga('send', 'pageview');</script></head>
- <body>
- <h2>Graph2d | Interpolation</h2>
- <div style="width:700px; font-size:14px; text-align: justify;">
- The Graph2d makes use of <a href="http://en.wikipedia.org/wiki/Centripetal_Catmull%E2%80%93Rom_spline" target="_blank">Catmull-Rom spline interpolation</a>.
- The user can configure these per group, or globally. In this example we show all 4 possiblities. The differences are in the parametrization of
- the curves. The options are <code>uniform</code>, <code>chordal</code> and <code>centripetal</code>. Alternatively you can disable the Catmull-Rom interpolation and
- a linear interpolation will be used. The <code>centripetal</code> parametrization produces the best result (no self intersection, yet follows the line closely) and is therefore the default setting.
- <br /><br />
- For both the <code>centripetal</code> and <code>chordal</code> parametrization, the distances between the points have to be calculated and this makes these methods computationally intensive
- if there are very many points. The <code>uniform</code> parametrization still has to do transformations, though it does not have to calculate the distance between point. Finally, the
- linear interpolation is the fastest method. For more on the Catmull-Rom method, <a href="http://www.cemyuksel.com/research/catmullrom_param/catmullrom.pdf" target="_blank">C. Yuksel et al. have an interesting paper titled ″On the parametrization of Catmull-Rom Curves″</a>.
- </div>
- <br />
- <div id="visualization"></div>
-
- <script type="text/javascript">
- // create a dataSet with groups
- var names = ['centripetal', 'chordal', 'uniform', 'disabled'];
- var groups = new vis.DataSet();
- groups.add({
- id: 0,
- content: names[0],
- options: {
- drawPoints: false,
- interpolation: {
- parametrization: 'centripetal'
- }
- }});
-
- groups.add({
- id: 1,
- content: names[1],
- options: {
- drawPoints: false,
- interpolation: {
- parametrization: 'chordal'
- }
- }});
-
- groups.add({
- id: 2,
- content: names[2],
- options: {
- drawPoints: false,
- interpolation: {
- parametrization: 'uniform'
- }
- }
- });
-
- groups.add({
- id: 3,
- content: names[3],
- options: {
- drawPoints: { style: 'circle' },
- interpolation: false
- }});
-
- var container = document.getElementById('visualization');
- var dataset = new vis.DataSet();
- for (var i = 0; i < names.length; i++) {
- dataset.add( [
- {x: '2014-06-12', y: 0 , group: i},
- {x: '2014-06-13', y: 40, group: i},
- {x: '2014-06-14', y: 10, group: i},
- {x: '2014-06-15', y: 15, group: i},
- {x: '2014-06-15', y: 30, group: i},
- {x: '2014-06-17', y: 10, group: i},
- {x: '2014-06-18', y: 15, group: i},
- {x: '2014-06-19', y: 52, group: i},
- {x: '2014-06-20', y: 10, group: i},
- {x: '2014-06-21', y: 20, group: i}
- ]);
- }
-
- var options = {
- dataPoints: false,
- dataAxis: {visible: false},
- legend: true,
- start: '2014-06-11',
- end: '2014-06-22'
- };
- var graph2d = new vis.Graph2d(container, dataset, groups, options);
-
- </script>
- </body>
- </html>
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