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