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

<!DOCTYPE html>
<html>
  <head>
    <title>Linear Regression</title>
    <!--
    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,
                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
	1	<!DOCTYPE html>
	2	<html>
	3	<head>
	4	<title>Linear Regression</title>
	5	<!--
	6	For production (minified) code, use:
	7	<script type="text/javascript" src="dygraph-combined.js"></script>
	8	-->
	9	<script type="text/javascript" src="../dygraph-dev.js"></script>
	10
	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 = "X,Y1,Y2\n";
	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	data += i + "," + i + "/120," + (i(120-i)) + "/" + (6060) + "\n";
	31	}
	32
	33	g = new Dygraph(
	34	document.getElementById("demodiv"),
	35	data,
	36	{
	37	underlayCallback: drawLines,
	38	drawPoints: true,
	39	strokeWidth: 0.0,
	40	fractions: true,
	41	errorBars: true,
	42	pointSize: 1
	43	}
	44	);
	45
	46	// coefficients of regression for each series.
	47	// if coeffs = [ null, [1, 2], null ] then we draw a regression for series 1
	48	// only. The regression line is y = 1 + 2 * x.
	49	var coeffs = [ null, null, null ];
	50	function regression(series) {
	51	// Only run the regression over visible points.
	52	var range = g.xAxisRange();
	53
	54	var sum_xy = 0.0, sum_x = 0.0, sum_y = 0.0, sum_x2 = 0.0, num = 0;
	55	for (var i = 0; i < g.numRows(); i++) {
	56	var x = g.getValue(i, 0);
	57	if (x < range[0] \|\| x > range[1]) continue;
	58
	59	var y = g.getValue(i, series);
	60	if (y == null) continue;
	61	if (y.length == 2) {
	62	// using fractions
	63	y = y[0] / y[1];
	64	}
	65
	66	num++;
	67	sum_x += x;
	68	sum_y += y;
	69	sum_xy += x * y;
	70	sum_x2 += x * x;
	71	}
	72
	73	var a = (sum_xy - sum_x * sum_y / num) / (sum_x2 - sum_x * sum_x / num);
	74	var b = (sum_y - a * sum_x) / num;
	75
	76	coeffs[series] = [b, a];
	77	if (typeof(console) != 'undefined') {
	78	console.log("coeffs(" + series + "): [" + b + ", " + a + "]");
	79	}
	80
	81	g.updateOptions({}); // forces a redraw.
	82	}
	83
	84	function clearLines() {
	85	for (var i = 0; i < coeffs.length; i++) coeffs[i] = null;
	86	g.updateOptions({});
	87	}
	88
	89	function toHex(rgb) {
	90	return 'rgb(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ')';
	91	}
	92
	93	function drawLines(ctx, area, layout) {
	94	if (typeof(g) == 'undefined') return; // won't be set on the initial draw.
	95
	96	var range = g.xAxisRange();
	97	for (var i = 0; i < coeffs.length; i++) {
	98	if (!coeffs[i]) continue;
	99	var a = coeffs[i][1];
	100	var b = coeffs[i][0];
	101
	102	var x1 = range[0];
	103	var y1 = a * x1 + b;
	104	var x2 = range[1];
	105	var y2 = a * x2 + b;
	106
	107	// Scale up to percentages, rather than fractions.
	108	y1 *= 100;
	109	y2 *= 100;
	110
	111	var p1 = g.toDomCoords(x1, y1);
	112	var p2 = g.toDomCoords(x2, y2);
	113
	114	var c = Dygraph.toRGB_(g.getColors()[i - 1]);
	115	c.r = Math.floor(255 - 0.5 * (255 - c.r));
	116	c.g = Math.floor(255 - 0.5 * (255 - c.g));
	117	c.b = Math.floor(255 - 0.5 * (255 - c.b));
	118	var color = toHex(c);
	119	ctx.save();
	120	ctx.strokeStyle = color;
	121	ctx.lineWidth = 2.0;
	122	ctx.beginPath();
	123	ctx.moveTo(p1[0], p1[1]);
	124	ctx.lineTo(p2[0], p2[1]);
	125	ctx.closePath();
	126	ctx.stroke();
	127	ctx.restore();
	128	}
	129	}
	130
	131	</script>
	132
	133	<div style="position: absolute; left: 500px; top: 150px;">
	134	<input type=button style="color: green;" value="Regression (Y1)" onClick="regression(1)" />
	135	<br/><br/>
	136	<input type=button style="color: blue;" value="Regression (Y2)" onClick="regression(2)" />
	137	<br/><br/>
	138	<input type=button value="Clear Lines" onClick="clearLines()" />
	139	</div>
	140	</body>
	141	</html>