ChartDirector 7.0 (PHP 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: phpdemo/paramcurve.php]
<?php require_once("../lib/phpchartdir.php"); # 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 = 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 = $c->addLegend(270, 30, false, "Arial Bold Italic", 10); $legendBox->setAlignment(TopCenter); $legendBox->setBackground(Transparent, 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", 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(PolynomialRegression(2)); $trend0->setHTMLImageMap("{disable}"); # Add a scatter layer for (dataX1, dataY1) $c->addScatterLayer($dataX1, $dataY1, "Exponential", GlassSphere2Shape, 11, 0x00aa00); # Add an exponential trend line layer for (dataX1, dataY1) $trend1 = $c->addTrendLayer2($dataX1, $dataY1, 0x00aa00); $trend1->setLineWidth(3); $trend1->setRegressionType(ExponentialRegression); $trend1->setHTMLImageMap("{disable}"); # Add a scatter layer using (dataX2, dataY2) $c->addScatterLayer($dataX2, $dataY2, "Logarithmic", GlassSphere2Shape, 11, 0x0000ff); # Add a logarithmic trend line layer for (dataX2, dataY2) $trend2 = $c->addTrendLayer2($dataX2, $dataY2, 0x0000ff); $trend2->setLineWidth(3); $trend2->setRegressionType(LogarithmicRegression); $trend2->setHTMLImageMap("{disable}"); # Output the chart $viewer = new WebChartViewer("chart1"); $viewer->setChart($c, 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.php?file=<?=basename(__FILE__)?>">View Chart Source Code</a> </div> <!-- ****** Here is the chart image ****** --> <?php echo $viewer->renderHTML(); ?> </body> </html>