[dygraphs.git] / tests / linear-regression-addseries.html

<html>
  <head>
    <title>Linear Regression</title>
    <!--[if IE]>
    <script type="text/javascript" src="../excanvas.js"></script>
    <![endif]-->
    <script type="text/javascript" src="../strftime/strftime-min.js"></script>
    <script type="text/javascript" src="../rgbcolor/rgbcolor.js"></script>
    <script type="text/javascript" src="../dygraph-canvas.js"></script>
    <script type="text/javascript" src="../dygraph.js"></script>
    <style type="text/css">
    body { max-width: 640 px; }
    </style>
  </head>
  <body>
    <h2>Linear Regression Demo</h2>
    <p>Click the buttons to generate linear regressions over either data
    series. If you zoom in and click the regression button, the regression will
    only be run over visible points. Zoom back out to see what the local
    regression looks like over the full data.</p>

    <div id="demodiv" style="width: 480px; height: 320px;"></div>

    <script type="text/javascript">
      var data = [];
      for (var i = 0; i < 120; i++) {
        data.push([i,
                   i / 5.0 + 10.0 * Math.sin(i / 3.0),
                   30.0 - i / 5.0 - 10.0 * Math.sin(i / 3.0 + 1.0)]);
      }
      var labels = ['X', 'Y1', 'Y2'];
      var orig_colors = [];

      g = new Dygraph(
              document.getElementById("demodiv"),
              data,
              {
                labels: labels,
                drawPoints: true,
                strokeWidth: 0.0,
                drawCallback: function(g, is_initial) {
                  if (!is_initial) return;
                  var c = g.getColors();
                  for (var i = 0; i < c.length; i++) orig_colors.push(c[i]);
                }
              }
          );

      // coefficients of regression for each series.
      // if coeffs = [ null, [1, 2], null ] then we draw a regression for series 1
      // only. The regression line is y = 1 + 2 * x.
      var coeffs = [ null, null, null ];
      function regression(series) {
        // Only run the regression over visible points.
        var range = g.xAxisRange();

        var sum_xy = 0.0, sum_x = 0.0, sum_y = 0.0, sum_x2 = 0.0, num = 0;
        for (var i = 0; i < data.length; i++) {
          var x = data[i][0];
          if (x < range[0] || x > range[1]) continue;

          var y = data[i][series];
          if (y == null) continue;
          if (y.length == 2) {
            // using fractions
            y = y[0] / y[1];
          }

          num++;
          sum_x += x;
          sum_y += y;
          sum_xy += x * y;
          sum_x2 += x * x;
        }

        var a = (sum_xy - sum_x * sum_y / num) / (sum_x2 - sum_x * sum_x / num);
        var b = (sum_y - a * sum_x) / num;

        coeffs[series] = [b, a];
        if (typeof(console) != 'undefined') {
          console.log("coeffs(" + series + "): [" + b + ", " + a + "]");
        }

        updateChart();
      }

      function updateChart() {
        // Generate a new data set with the regression lines.
        var new_labels = [];
        var new_colors = [];
        var new_opts = {};
        for (var i = 0; i < labels.length; i++) {
          new_labels.push(labels[i]);
          if (i) new_colors.push(orig_colors[i - 1]);
          if (coeffs[i]) {
            // Darken the series by 50% to generate its regression.
            var label = labels[i] + " Regression";
            new_labels.push(label);
            var c = new RGBColor(orig_colors[i - 1]);
            c.r = Math.floor(255 - 0.5 * (255 - c.r));
            c.g = Math.floor(255 - 0.5 * (255 - c.g));
            c.b = Math.floor(255 - 0.5 * (255 - c.b));
            new_colors.push(c.toHex());
            new_opts[label] = {
              drawPoints: false,
              strokeWidth: 1.0
            };
          }
        }

        var new_data = [];
        for (var i = 0; i < data.length; i++) {
          new_data.push([]);
          for (var j = 0; j < data[i].length; j++) {
            new_data[i].push(data[i][j]);
            if (coeffs[j]) {
              new_data[i].push(coeffs[j][0] + coeffs[j][1] * data[i][0]);
            }
          }
        }

        new_opts.file = new_data;
        new_opts.labels = new_labels;
        new_opts.colors = new_colors;
        g.updateOptions(new_opts);
      }

      function clearLines() {
        for (var i = 0; i < coeffs.length; i++) coeffs[i] = null;
        updateChart();
      }
      
    </script>
    
    <div style="position: absolute; left: 500px; top: 150px;">
    <input type=button style="color: green;" value="Regression (Y1)" onClick="regression(1)" />
    <br/><br/>
    <input type=button style="color: blue;" value="Regression (Y2)" onClick="regression(2)" />
    <br/><br/>
    <input type=button value="Clear Lines" onClick="clearLines()" />
    </div>
</body>
</html>
Commit	Line	Data
34bbe78b DV	1	<html>
	2	<head>
	3	<title>Linear Regression</title>
	4	<!--[if IE]>
a2b2c3a1	5	<script type="text/javascript" src="../excanvas.js"></script>
34bbe78b DV	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	<style type="text/css">
	12	body { max-width: 640 px; }
	13	</style>
	14	</head>
	15	<body>
	16	<h2>Linear Regression Demo</h2>
	17	<p>Click the buttons to generate linear regressions over either data
	18	series. If you zoom in and click the regression button, the regression will
	19	only be run over visible points. Zoom back out to see what the local
	20	regression looks like over the full data.</p>
	21
	22	<div id="demodiv" style="width: 480px; height: 320px;"></div>
	23
	24	<script type="text/javascript">
	25	var data = [];
	26	for (var i = 0; i < 120; i++) {
	27	data.push([i,
	28	i / 5.0 + 10.0 * Math.sin(i / 3.0),
	29	30.0 - i / 5.0 - 10.0 * Math.sin(i / 3.0 + 1.0)]);
	30	}
	31	var labels = ['X', 'Y1', 'Y2'];
	32	var orig_colors = [];
	33
	34	g = new Dygraph(
	35	document.getElementById("demodiv"),
	36	data,
	37	{
	38	labels: labels,
	39	drawPoints: true,
de0445fc	40	strokeWidth: 0.0,
34bbe78b DV	41	drawCallback: function(g, is_initial) {
	42	if (!is_initial) return;
	43	var c = g.getColors();
	44	for (var i = 0; i < c.length; i++) orig_colors.push(c[i]);
	45	}
	46	}
	47	);
	48
	49	// coefficients of regression for each series.
	50	// if coeffs = [ null, [1, 2], null ] then we draw a regression for series 1
	51	// only. The regression line is y = 1 + 2 * x.
	52	var coeffs = [ null, null, null ];
	53	function regression(series) {
	54	// Only run the regression over visible points.
	55	var range = g.xAxisRange();
	56
	57	var sum_xy = 0.0, sum_x = 0.0, sum_y = 0.0, sum_x2 = 0.0, num = 0;
	58	for (var i = 0; i < data.length; i++) {
	59	var x = data[i][0];
	60	if (x < range[0] \|\| x > range[1]) continue;
	61
	62	var y = data[i][series];
	63	if (y == null) continue;
d1dfab80 DV	64	if (y.length == 2) {
	65	// using fractions
	66	y = y[0] / y[1];
	67	}
34bbe78b DV	68
	69	num++;
	70	sum_x += x;
	71	sum_y += y;
	72	sum_xy += x * y;
	73	sum_x2 += x * x;
	74	}
	75
	76	var a = (sum_xy - sum_x * sum_y / num) / (sum_x2 - sum_x * sum_x / num);
	77	var b = (sum_y - a * sum_x) / num;
	78
	79	coeffs[series] = [b, a];
4df1af70	80	if (typeof(console) != 'undefined') {
34bbe78b DV	81	console.log("coeffs(" + series + "): [" + b + ", " + a + "]");
	82	}
	83
	84	updateChart();
	85	}
	86
	87	function updateChart() {
	88	// Generate a new data set with the regression lines.
	89	var new_labels = [];
	90	var new_colors = [];
de0445fc	91	var new_opts = {};
34bbe78b DV	92	for (var i = 0; i < labels.length; i++) {
	93	new_labels.push(labels[i]);
	94	if (i) new_colors.push(orig_colors[i - 1]);
	95	if (coeffs[i]) {
	96	// Darken the series by 50% to generate its regression.
227b93cc DV	97	var label = labels[i] + " Regression";
227b93cc DV	98	new_labels.push(label);
34bbe78b DV	99	var c = new RGBColor(orig_colors[i - 1]);
	100	c.r = Math.floor(255 - 0.5 * (255 - c.r));
	101	c.g = Math.floor(255 - 0.5 * (255 - c.g));
	102	c.b = Math.floor(255 - 0.5 * (255 - c.b));
	103	new_colors.push(c.toHex());
227b93cc	104	new_opts[label] = {
de0445fc DV	105	drawPoints: false,
	106	strokeWidth: 1.0
	107	};
34bbe78b DV	108	}
	109	}
	110
	111	var new_data = [];
	112	for (var i = 0; i < data.length; i++) {
	113	new_data.push([]);
	114	for (var j = 0; j < data[i].length; j++) {
	115	new_data[i].push(data[i][j]);
	116	if (coeffs[j]) {
	117	new_data[i].push(coeffs[j][0] + coeffs[j][1] * data[i][0]);
	118	}
	119	}
	120	}
	121
de0445fc DV	122	new_opts.file = new_data;
	123	new_opts.labels = new_labels;
	124	new_opts.colors = new_colors;
	125	g.updateOptions(new_opts);
34bbe78b DV	126	}
	127
	128	function clearLines() {
	129	for (var i = 0; i < coeffs.length; i++) coeffs[i] = null;
	130	updateChart();
	131	}
34bbe78b DV	132
	133	</script>
	134
	135	<div style="position: absolute; left: 500px; top: 150px;">
	136	<input type=button style="color: green;" value="Regression (Y1)" onClick="regression(1)" />
	137	<br/><br/>
	138	<input type=button style="color: blue;" value="Regression (Y2)" onClick="regression(2)" />
	139	<br/><br/>
	140	<input type=button value="Clear Lines" onClick="clearLines()" />
	141	</div>
	142	</body>
	143	</html>