tests/plotter.html

   1 <!DOCTYPE html>
   2 <html>
   3   <head>
   4     <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9">
   5     <title>dygraphs Equation Plotter</title>
   6     <!--[if IE]>
   7     <script type="text/javascript" src="../excanvas.js"></script>
   8     <![endif]-->
   9     <script type="text/javascript" src="../strftime/strftime-min.js"></script>
  10     <script type="text/javascript" src="../rgbcolor/rgbcolor.js"></script>
  11     <script type="text/javascript" src="../dygraph-canvas.js"></script>
  12     <script type="text/javascript" src="../dygraph.js"></script>
  13     <script type="text/javascript">
  14       function plot() {
  15         var eq = document.getElementById("eq").value;
  16         eval("fn = " + eq);
  17
  18         var graph = document.getElementById("graph_div");
  19         var width = parseInt(graph.style.width);
  20         var x1 = parseFloat(document.getElementById("x1").value);
  21         var x2 = parseFloat(document.getElementById("x2").value);
  22         var xs = 1.0 * (x2 - x1) / width;
  23
  24         var data = [];
  25         for (var i = 0; i < width; i++) {
  26           var x = x1 + i * xs;
  27           var y = fn(x);
  28           var row = [x];
  29           if (y.length > 0) {
  30             for (var j = 0; j < y.length; j++) {
  31               row.push(y[j]);
  32             }
  33           } else {
  34             row.push(y);
  35           }
  36           data.push(row);
  37         }
  38
  39         g = new Dygraph(graph, data);
  40       }
  41
  42       function preset() {
  43         var sel = document.getElementById("presets").selectedIndex;
  44         var id = document.getElementById("presets").options[sel].id;
  45         var presets = {
  46           'id': [ -10, 10, 'function(x) {\n  return x;\n}' ],
  47           'sine': [ -10, 10, 'function(x) {\n  return Math.sin(x);\n}' ],
  48           'taylor': [ -3, 3, 'function(x) {\n  return [Math.cos(x), 1 - x*x/2 + x*x*x*x/24];\n}' ],
  49           '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}' ]
  50         };
  51
  52         if (id == "custom") { return; }
  53         document.getElementById("x1").value = presets[id][0];
  54         document.getElementById("x2").value = presets[id][1];
  55         document.getElementById("eq").value = presets[id][2];
  56         plot();
  57       }
  58     </script>
  59   </head>
  60   <body onload="preset()">
  61     <p><b>Equation: </b><br/>
  62     <textarea cols="40" rows="10" id="eq">function(x) {
  63   return [0.1 * x, 0.1 * x + Math.sin(x), 0.1*x + Math.cos(x)];
  64 }</textarea><br/>
  65 <b>Preset functions:</b> <select id=presets onchange="preset()">
  66 <option id=custom>(custom)</option>
  67 <option id=id>Identity</option>
  68 <option id=sine>Sine Wave</option>
  69 <option id=taylor>Taylor series</option>
  70 <option selected id=sawtooth>Sawtooth</option>
  71 </select>
  72     </p>
  73
  74     <p><b>x range: </b> <input type=text width="5" id="x1" value="-10" />
  75     to <input type=text width="5" id="x2" value="10" /></p>
  76     <p><input type=button value="Plot" onClick="plot()" /></p>
  77
  78     <div id="graph_div" style="width:1024px; height:400px;"></div>
  79   </body>
  80 </html>