ChartDirector 7.0 (Java 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

[JSP Version] jspdemo/paramcurve.jsp
<%@page import="ChartDirector.*, java.util.*" %> <% // The XY data of the first data series double[] dataX0 = {10, 35, 17, 4, 22, 29, 45, 52, 63, 39}; double[] dataY0 = {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 double[] dataX1 = {30, 35, 17, 4, 22, 59, 43, 52, 63, 39}; double[] dataY1 = {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 double[] dataX2 = {28, 35, 15, 10, 22, 60, 46, 64, 39}; double[] dataY2 = {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 XYChart c = new 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 legendBox = c.addLegend(270, 30, false, "Arial Bold Italic", 10); legendBox.setAlignment(Chart.TopCenter); legendBox.setBackground(Chart.Transparent, Chart.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", Chart.GlassSphere2Shape, 11, 0xff0000); // Add a degree 2 polynomial trend line layer for (dataX0, dataY0) TrendLayer trend0 = c.addTrendLayer2(dataX0, dataY0, 0xff0000); trend0.setLineWidth(3); trend0.setRegressionType(Chart.PolynomialRegression(2)); trend0.setHTMLImageMap("{disable}"); // Add a scatter layer for (dataX1, dataY1) c.addScatterLayer(dataX1, dataY1, "Exponential", Chart.GlassSphere2Shape, 11, 0x00aa00); // Add an exponential trend line layer for (dataX1, dataY1) TrendLayer trend1 = c.addTrendLayer2(dataX1, dataY1, 0x00aa00); trend1.setLineWidth(3); trend1.setRegressionType(Chart.ExponentialRegression); trend1.setHTMLImageMap("{disable}"); // Add a scatter layer using (dataX2, dataY2) c.addScatterLayer(dataX2, dataY2, "Logarithmic", Chart.GlassSphere2Shape, 11, 0x0000ff); // Add a logarithmic trend line layer for (dataX2, dataY2) TrendLayer trend2 = c.addTrendLayer2(dataX2, dataY2, 0x0000ff); trend2.setLineWidth(3); trend2.setRegressionType(Chart.LogarithmicRegression); trend2.setHTMLImageMap("{disable}"); // Output the chart WebChartViewer viewer = new WebChartViewer(request, "chart1"); viewer.setChart(c, Chart.SVG); // Include tool tip for the chart viewer.setImageMap(c.getHTMLImageMap("", "", "title='[{dataSetName}] ({x}, {value})'")); %> <!DOCTYPE html> <html> <head> <title>Parametric Curve Fitting</title> <!-- Include ChartDirector Javascript Library to support chart interactions --> <script type="text/javascript" src="cdjcv.js"></script> </head> <body style="margin:5px 0px 0px 5px"> <div style="font:bold 18pt verdana;"> Parametric Curve Fitting </div> <hr style="border:solid 1px #000080; background:#000080" /> <div style="font:10pt verdana; margin-bottom:1.5em"> <a href="viewsource.jsp?file=<%=request.getServletPath()%>">View Source Code</a> </div> <!-- ****** Here is the chart image ****** --> <%= viewer.renderHTML(response) %> </body> </html>