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

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9">
    <title>Linear Regression</title>
    <!--[if IE]>
    <script type="text/javascript" src="../excanvas.js"></script>
    <![endif]-->
    <!--
    For production (minified) code, use:
    <script type="text/javascript" src="dygraph-combined.js"></script>
    -->
    <script type="text/javascript" src="../dygraph-dev.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 = "X,Y1,Y2\n";
      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)]);
        data += i + "," + i + "/120," + (i*(120-i)) + "/" + (60*60) + "\n";
      }

      g = new Dygraph(
              document.getElementById("demodiv"),
              data,
              {
                underlayCallback: drawLines,
                drawPoints: true,
                strokeWidth: 0.0,
                fractions: true,
                errorBars: true
              }
          );

      // 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 < g.numRows(); i++) {
          var x = g.getValue(i, 0);
          if (x < range[0] || x > range[1]) continue;

          var y = g.getValue(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 + "]");
        }

        g.updateOptions({});  // forces a redraw.
      }

      function clearLines() {
        for (var i = 0; i < coeffs.length; i++) coeffs[i] = null;
        g.updateOptions({});
      }

      function drawLines(ctx, area, layout) {
        if (typeof(g) == 'undefined') return;  // won't be set on the initial draw.

        var range = g.xAxisRange();
        for (var i = 0; i < coeffs.length; i++) {
          if (!coeffs[i]) continue;
          var a = coeffs[i][1];
          var b = coeffs[i][0];

          var x1 = range[0];
          var y1 = a * x1 + b;
          var x2 = range[1];
          var y2 = a * x2 + b;

          // Scale up to percentages, rather than fractions.
          y1 *= 100;
          y2 *= 100;

          var p1 = g.toDomCoords(x1, y1);
          var p2 = g.toDomCoords(x2, y2);

          var c = new RGBColorParser(g.getColors()[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));
          var color = c.toHex();
          ctx.save();
          ctx.strokeStyle = color;
          ctx.lineWidth = 1.0;
          ctx.beginPath();
          ctx.moveTo(p1[0], p1[1]);
          ctx.lineTo(p2[0], p2[1]);
          ctx.closePath();
          ctx.stroke();
          ctx.restore();
        }
      }
      
    </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
	1	<!DOCTYPE html>
	2	<html>
	3	<head>
	4	<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9">
	5	<title>Linear Regression</title>
	6	<!--[if IE]>
	7	<script type="text/javascript" src="../excanvas.js"></script>
	8	<![endif]-->
	9	<!--
	10	For production (minified) code, use:
	11	<script type="text/javascript" src="dygraph-combined.js"></script>
	12	-->
	13	<script type="text/javascript" src="../dygraph-dev.js"></script>
	14
	15	<style type="text/css">
	16	body { max-width: 640 px; }
	17	</style>
	18	</head>
	19	<body>
	20	<h2>Linear Regression Demo</h2>
	21	<p>Click the buttons to generate linear regressions over either data
	22	series. If you zoom in and click the regression button, the regression will
	23	only be run over visible points. Zoom back out to see what the local
	24	regression looks like over the full data.</p>
	25
	26	<div id="demodiv" style="width: 480px; height: 320px;"></div>
	27
	28	<script type="text/javascript">
	29	var data = "X,Y1,Y2\n";
	30	for (var i = 0; i < 120; i++) {
	31	// data.push([i,
	32	// i / 5.0 + 10.0 * Math.sin(i / 3.0),
	33	// 30.0 - i / 5.0 - 10.0 * Math.sin(i / 3.0 + 1.0)]);
	34	data += i + "," + i + "/120," + (i(120-i)) + "/" + (6060) + "\n";
	35	}
	36
	37	g = new Dygraph(
	38	document.getElementById("demodiv"),
	39	data,
	40	{
	41	underlayCallback: drawLines,
	42	drawPoints: true,
	43	strokeWidth: 0.0,
	44	fractions: true,
	45	errorBars: true
	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 < g.numRows(); i++) {
	59	var x = g.getValue(i, 0);
	60	if (x < range[0] \|\| x > range[1]) continue;
	61
	62	var y = g.getValue(i, series);
	63	if (y == null) continue;
	64	if (y.length == 2) {
	65	// using fractions
	66	y = y[0] / y[1];
	67	}
	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];
	80	if (typeof(console) != 'undefined') {
	81	console.log("coeffs(" + series + "): [" + b + ", " + a + "]");
	82	}
	83
	84	g.updateOptions({}); // forces a redraw.
	85	}
	86
	87	function clearLines() {
	88	for (var i = 0; i < coeffs.length; i++) coeffs[i] = null;
	89	g.updateOptions({});
	90	}
	91
	92	function drawLines(ctx, area, layout) {
	93	if (typeof(g) == 'undefined') return; // won't be set on the initial draw.
	94
	95	var range = g.xAxisRange();
	96	for (var i = 0; i < coeffs.length; i++) {
	97	if (!coeffs[i]) continue;
	98	var a = coeffs[i][1];
	99	var b = coeffs[i][0];
	100
	101	var x1 = range[0];
	102	var y1 = a * x1 + b;
	103	var x2 = range[1];
	104	var y2 = a * x2 + b;
	105
	106	// Scale up to percentages, rather than fractions.
	107	y1 *= 100;
	108	y2 *= 100;
	109
	110	var p1 = g.toDomCoords(x1, y1);
	111	var p2 = g.toDomCoords(x2, y2);
	112
	113	var c = new RGBColorParser(g.getColors()[i - 1]);
	114	c.r = Math.floor(255 - 0.5 * (255 - c.r));
	115	c.g = Math.floor(255 - 0.5 * (255 - c.g));
	116	c.b = Math.floor(255 - 0.5 * (255 - c.b));
	117	var color = c.toHex();
	118	ctx.save();
	119	ctx.strokeStyle = color;
	120	ctx.lineWidth = 1.0;
	121	ctx.beginPath();
	122	ctx.moveTo(p1[0], p1[1]);
	123	ctx.lineTo(p2[0], p2[1]);
	124	ctx.closePath();
	125	ctx.stroke();
	126	ctx.restore();
	127	}
	128	}
	129
	130	</script>
	131
	132	<div style="position: absolute; left: 500px; top: 150px;">
	133	<input type=button style="color: green;" value="Regression (Y1)" onClick="regression(1)" />
	134	<br/><br/>
	135	<input type=button style="color: blue;" value="Regression (Y2)" onClick="regression(2)" />
	136	<br/><br/>
	137	<input type=button value="Clear Lines" onClick="clearLines()" />
	138	</div>
	139	</body>
	140	</html>