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

<!DOCTYPE html>
<html>
  <head>
    <link rel="stylesheet" href="../dist/dygraph.css">
    <title>Linear Regression</title>
    <script type="text/javascript" src="../dist/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 = "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,
                pointSize: 1
              }
          );

      // 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 toHex(rgb) {
        return 'rgb(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ')';
      }

      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 = Dygraph.toRGB_(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 = toHex(c);
          ctx.save();
          ctx.strokeStyle = color;
          ctx.lineWidth = 2.0;
          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
54425b14	1	<!DOCTYPE html>
d1dfab80 DV	2	<html>
d1dfab80 DV	3	<head>
fd6b8dad	4	<link rel="stylesheet" href="../dist/dygraph.css">
d1dfab80	5	<title>Linear Regression</title>
fbd6834a	6	<script type="text/javascript" src="../dist/dygraph.js"></script>
7e5ddc94	7
d1dfab80 DV	8	<style type="text/css">
	9	body { max-width: 640 px; }
	10	</style>
	11	</head>
	12	<body>
	13	<h2>Linear Regression Demo</h2>
	14	<p>Click the buttons to generate linear regressions over either data
	15	series. If you zoom in and click the regression button, the regression will
	16	only be run over visible points. Zoom back out to see what the local
	17	regression looks like over the full data.</p>
	18
	19	<div id="demodiv" style="width: 480px; height: 320px;"></div>
	20
	21	<script type="text/javascript">
	22	var data = "X,Y1,Y2\n";
	23	for (var i = 0; i < 120; i++) {
	24	// data.push([i,
	25	// i / 5.0 + 10.0 * Math.sin(i / 3.0),
	26	// 30.0 - i / 5.0 - 10.0 * Math.sin(i / 3.0 + 1.0)]);
	27	data += i + "," + i + "/120," + (i(120-i)) + "/" + (6060) + "\n";
	28	}
	29
	30	g = new Dygraph(
	31	document.getElementById("demodiv"),
	32	data,
	33	{
	34	underlayCallback: drawLines,
	35	drawPoints: true,
	36	strokeWidth: 0.0,
	37	fractions: true,
0a171c09 DV	38	errorBars: true,
0a171c09 DV	39	pointSize: 1
d1dfab80 DV	40	}
	41	);
	42
	43	// coefficients of regression for each series.
	44	// if coeffs = [ null, [1, 2], null ] then we draw a regression for series 1
	45	// only. The regression line is y = 1 + 2 * x.
	46	var coeffs = [ null, null, null ];
	47	function regression(series) {
	48	// Only run the regression over visible points.
	49	var range = g.xAxisRange();
	50
	51	var sum_xy = 0.0, sum_x = 0.0, sum_y = 0.0, sum_x2 = 0.0, num = 0;
	52	for (var i = 0; i < g.numRows(); i++) {
	53	var x = g.getValue(i, 0);
	54	if (x < range[0] \|\| x > range[1]) continue;
	55
	56	var y = g.getValue(i, series);
	57	if (y == null) continue;
	58	if (y.length == 2) {
	59	// using fractions
	60	y = y[0] / y[1];
	61	}
	62
	63	num++;
	64	sum_x += x;
	65	sum_y += y;
	66	sum_xy += x * y;
	67	sum_x2 += x * x;
	68	}
	69
	70	var a = (sum_xy - sum_x * sum_y / num) / (sum_x2 - sum_x * sum_x / num);
	71	var b = (sum_y - a * sum_x) / num;
	72
	73	coeffs[series] = [b, a];
	74	if (typeof(console) != 'undefined') {
	75	console.log("coeffs(" + series + "): [" + b + ", " + a + "]");
	76	}
	77
	78	g.updateOptions({}); // forces a redraw.
	79	}
	80
	81	function clearLines() {
	82	for (var i = 0; i < coeffs.length; i++) coeffs[i] = null;
	83	g.updateOptions({});
	84	}
	85
0a171c09 DV	86	function toHex(rgb) {
	87	return 'rgb(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ')';
	88	}
	89
d1dfab80 DV	90	function drawLines(ctx, area, layout) {
	91	if (typeof(g) == 'undefined') return; // won't be set on the initial draw.
	92
	93	var range = g.xAxisRange();
	94	for (var i = 0; i < coeffs.length; i++) {
	95	if (!coeffs[i]) continue;
	96	var a = coeffs[i][1];
	97	var b = coeffs[i][0];
	98
	99	var x1 = range[0];
	100	var y1 = a * x1 + b;
	101	var x2 = range[1];
	102	var y2 = a * x2 + b;
	103
	104	// Scale up to percentages, rather than fractions.
	105	y1 *= 100;
	106	y2 *= 100;
	107
	108	var p1 = g.toDomCoords(x1, y1);
	109	var p2 = g.toDomCoords(x2, y2);
	110
0a171c09	111	var c = Dygraph.toRGB_(g.getColors()[i - 1]);
d1dfab80 DV	112	c.r = Math.floor(255 - 0.5 * (255 - c.r));
	113	c.g = Math.floor(255 - 0.5 * (255 - c.g));
	114	c.b = Math.floor(255 - 0.5 * (255 - c.b));
0a171c09	115	var color = toHex(c);
d1dfab80 DV	116	ctx.save();
d1dfab80 DV	117	ctx.strokeStyle = color;
0a171c09	118	ctx.lineWidth = 2.0;
d1dfab80 DV	119	ctx.beginPath();
	120	ctx.moveTo(p1[0], p1[1]);
	121	ctx.lineTo(p2[0], p2[1]);
	122	ctx.closePath();
	123	ctx.stroke();
	124	ctx.restore();
	125	}
	126	}
	127
	128	</script>
	129
	130	<div style="position: absolute; left: 500px; top: 150px;">
	131	<input type=button style="color: green;" value="Regression (Y1)" onClick="regression(1)" />
	132	<br/><br/>
	133	<input type=button style="color: blue;" value="Regression (Y2)" onClick="regression(2)" />
	134	<br/><br/>
	135	<input type=button value="Clear Lines" onClick="clearLines()" />
	136	</div>
	137	</body>
	138	</html>