ChartDirector 6.0 (ColdFusion Edition)

Parametric Curve Fitting




This example demonstrates parametric curve fitting.

In addition to linear regression, ChartDirector also supports polynomial, exponential and logarithmic regression. To create these curves, a TrendLayer object is created using XYChart.addTrendLayer, and the regressive type is set using TrendLayer.setRegressionType.

Source Code Listing

[File: cfdemo/paramcurve.cfm]
<cfscript>

// ChartDirector for ColdFusion API Access Point
cd = CreateObject("java", "ChartDirector.CFChart");

// A utility to allow us to create arrays with data in one line of code
function Array() {
    var result = ArrayNew(1);
    var i = 0;
    for (i = 1; i LTE ArrayLen(arguments); i = i + 1)
        result[i] = arguments[i];
    return result;
}

// The XY data of the first data series
dataX0 = Array(10, 35, 17, 4, 22, 29, 45, 52, 63, 39);
dataY0 = Array(2.0, 3.2, 2.7, 1.2, 2.8, 2.9, 3.1, 3.0, 2.3, 3.3);

// The XY data of the second data series
dataX1 = Array(30, 35, 17, 4, 22, 59, 43, 52, 63, 39);
dataY1 = Array(1.0, 1.3, 0.7, 0.6, 0.8, 3.0, 1.8, 2.3, 3.4, 1.5);

// The XY data of the third data series
dataX2 = Array(28, 35, 15, 10, 22, 60, 46, 64, 39);
dataY2 = Array(2.0, 2.2, 1.2, 0.4, 1.8, 2.7, 2.4, 2.8, 2.4);

// Create a XYChart object of size 540 x 480 pixels
c = cd.XYChart(540, 480);

// Set the plotarea at (70, 65) and of size 400 x 350 pixels, with white background and a light grey
// border (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color
// (0xc0c0c0)
c.setPlotArea(70, 65, 400, 350, "0xffffff", -1, "0xc0c0c0", "0xc0c0c0", -1);

// Add a legend box with the top center point anchored at (270, 30). Use horizontal layout. Use 10pt
// Arial Bold Italic font. Set the background and border color to Transparent.
legendBox = c.addLegend(270, 30, False, "Arial Bold Italic", 10);
legendBox.setAlignment(cd.TopCenter);
legendBox.setBackground(cd.Transparent, cd.Transparent);

// Add a title to the chart using 18 point Times Bold Itatic font.
c.addTitle("Parametric Curve Fitting", "Times New Roman Bold Italic", 18);

// Add titles to the axes using 12pt Arial Bold Italic font
c.yAxis().setTitle("Axis Title Placeholder", "Arial Bold Italic", 12);
c.xAxis().setTitle("Axis Title Placeholder", "Arial Bold Italic", 12);

// Set the axes line width to 3 pixels
c.yAxis().setWidth(3);
c.xAxis().setWidth(3);

// Add a scatter layer using (dataX0, dataY0)
c.addScatterLayer(dataX0, dataY0, "Polynomial", cd.GlassSphere2Shape, 11, "0xff0000");

// Add a degree 2 polynomial trend line layer for (dataX0, dataY0)
trend0 = c.addTrendLayer2(dataX0, dataY0, "0xff0000");
trend0.setLineWidth(3);
trend0.setRegressionType(cd.PolynomialRegression(2));
trend0.setHTMLImageMap("{disable}");

// Add a scatter layer for (dataX1, dataY1)
c.addScatterLayer(dataX1, dataY1, "Exponential", cd.GlassSphere2Shape, 11, "0x00aa00");

// Add an exponential trend line layer for (dataX1, dataY1)
trend1 = c.addTrendLayer2(dataX1, dataY1, "0x00aa00");
trend1.setLineWidth(3);
trend1.setRegressionType(cd.ExponentialRegression);
trend1.setHTMLImageMap("{disable}");

// Add a scatter layer using (dataX2, dataY2)
c.addScatterLayer(dataX2, dataY2, "Logarithmic", cd.GlassSphere2Shape, 11, "0x0000ff");

// Add a logarithmic trend line layer for (dataX2, dataY2)
trend2 = c.addTrendLayer2(dataX2, dataY2, "0x0000ff");
trend2.setLineWidth(3);
trend2.setRegressionType(cd.LogarithmicRegression);
trend2.setHTMLImageMap("{disable}");

// Output the chart
chart1URL = c.makeSession(GetPageContext(), "chart1");

// Include tool tip for the chart
imageMap1 = c.getHTMLImageMap("", "", "title='[{dataSetName}] ({x}, {value})'");

</cfscript>
<html>
<body style="margin:5px 0px 0px 5px">
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    Parametric Curve Fitting
</div>
<hr style="border:solid 1px #000080" />
<cfoutput>
<div style="font-size:9pt; font-family:verdana; margin-bottom:1.5em">
    <a href='viewsource.cfm?file=#CGI.SCRIPT_NAME#'>View Source Code</a>
</div>
<img src="getchart.cfm?#chart1URL#" usemap="##map1" border="0" />
<map name="map1">#imageMap1#</map>
</cfoutput>
</body>
</html>