tests/plotter.html

   1 <html>
   2   <head>
   3     <title>dygraphs Equation Plotter</title>
   4     <!--[if IE]>
   5     <script type="text/javascript" src="excanvas.js"></script>
   6     <![endif]-->
   7     <script type="text/javascript" src="../dygraph-combined.js"></script>
   8     <script type="text/javascript" src="../dygraph-canvas.js"></script>
   9     <script type="text/javascript" src="../dygraph.js"></script>
  10     <script type="text/javascript">
  11       function plot() {
  12         var eq = document.getElementById("eq").value;
  13         eval("fn = " + eq);
  14
  15         var graph = document.getElementById("graph_div");
  16         var width = parseInt(graph.style.width);
  17         var x1 = parseFloat(document.getElementById("x1").value);
  18         var x2 = parseFloat(document.getElementById("x2").value);
  19         var xs = 1.0 * (x2 - x1) / width;
  20
  21         var data = [];
  22         for (var i = 0; i < width; i++) {
  23           var x = x1 + i * xs;
  24           var y = fn(x);
  25           var row = [x];
  26           if (y.length > 0) {
  27             for (var j = 0; j < y.length; j++) {
  28               row.push(y[j]);
  29             }
  30           } else {
  31             row.push(y);
  32           }
  33           data.push(row);
  34         }
  35
  36         g = new Dygraph(graph, data);
  37       }
  38
  39       function preset() {
  40         var sel = document.getElementById("presets").selectedIndex;
  41         var id = document.getElementById("presets").options[sel].id;
  42         var presets = {
  43           'id': [ -10, 10, 'function(x) {\n  return x;\n}' ],
  44           'sine': [ -10, 10, 'function(x) {\n  return Math.sin(x);\n}' ],
  45           'taylor': [ -3, 3, 'function(x) {\n  return [Math.cos(x), 1 - x*x/2 + x*x*x*x/24];\n}' ],
  46           'sawtooth': [-10, 10, 'function(x) {\n  var y = 0;\n  for (var i = 1; i < 20; i+=2) {\n    y += Math.sin(i * x)/i;\n  }\n  var final = 1 - 2*(Math.abs(Math.floor(x / Math.PI)) % 2);\n  return [4/Math.PI * y, final];\n}' ]
  47         };
  48
  49         if (id == "custom") { return; }
  50         document.getElementById("x1").value = presets[id][0];
  51         document.getElementById("x2").value = presets[id][1];
  52         document.getElementById("eq").value = presets[id][2];
  53         plot();
  54       }
  55     </script>
  56   </head>
  57   <body onload="preset()">
  58     <p><b>Equation: </b><br/>
  59     <textarea cols="40" rows="10" id="eq">function(x) {
  60   return [0.1 * x, 0.1 * x + Math.sin(x), 0.1*x + Math.cos(x)];
  61 }</textarea><br/>
  62 <b>Preset functions:</b> <select id=presets onchange="preset()">
  63 <option id=custom>(custom)</option>
  64 <option id=id>Identity</option>
  65 <option id=sine>Sine Wave</option>
  66 <option id=taylor>Taylor series</option>
  67 <option selected id=sawtooth>Sawtooth</option>
  68 </select>
  69     </p>
  70
  71     <p><b>x range: </b> <input type=text width="5" id="x1" value="-10" />
  72     to <input type=text width="5" id="x2" value="10" /></p>
  73     <p><input type=button value="Plot" onClick="plot()" /></p>
  74
  75     <div id="graph_div" style="width:1024px; height:400px;"></div>
  76   </body>
  77 </html>