curvefitting.php
Back to Chart Graphics
<![CDATA[
<?php
require_once("../lib/phpchartdir.php");
# Use random table to generate a random series. The random table is set to 1 col x 51 rows, with 9
# as the seed
$rantable = new RanTable(9, 1, 51);
# Set the 1st column to start from 100, with changes between rows from -5 to +5
$rantable->setCol(0, 100, -5, 5);
# Get the 1st column of the random table as the data set
$data = $rantable->getCol(0);
# Create a XYChart object of size 600 x 300 pixels
$c = new XYChart(600, 300);
# Set the plotarea at (50, 35) and of size 500 x 240 pixels. Enable both the horizontal and vertical
# grids by setting their colors to grey (0xc0c0c0)
$c->setPlotArea(50, 35, 500, 240)->setGridColor(0xc0c0c0, 0xc0c0c0);
# Add a title to the chart using 18 point Times Bold Itatic font.
$c->addTitle("LOWESS Generic Curve Fitting Algorithm", "Times New Roman Bold Italic", 18);
# Set the y axis line width to 3 pixels
$c->yAxis->setWidth(3);
# Add a title to the x axis using 12pt Arial Bold Italic font
$c->xAxis->setTitle("Server Load (TPS)", "Arial Bold Italic", 12);
# Set the x axis line width to 3 pixels
$c->xAxis->setWidth(3);
# Set the x axis scale from 0 - 50, with major tick every 5 units and minor tick every 1 unit
$c->xAxis->setLinearScale(0, 50, 5, 1);
# Add a blue layer to the chart
$layer = $c->addLineLayer2();
# Add a red (0x80ff0000) data set to the chart with square symbols
$layer->addDataSet($data, 0x80ff0000)->setDataSymbol(SquareSymbol);
# Set the line width to 2 pixels
$layer->setLineWidth(2);
# Use lowess for curve fitting, and plot the fitted data using a spline layer with line width set to
# 3 pixels
$curve = new ArrayMath($data);
$curve->lowess();
$c->addSplineLayer($curve->result(), 0x0000ff)->setLineWidth(3);
# Set zero affinity to 0 to make sure the line is displayed in the most detail scale
$c->yAxis->setAutoScale(0, 0, 0);
# Output the chart
$viewer = new WebChartViewer("chart1");
$viewer->setChart($c, SVG);
# Include tool tip for the chart
$viewer->setImageMap($c->getHTMLImageMap("", "", "title='({x}, {value|2})'"));
?>
<!DOCTYPE html>
<html>
<head>
<title>General 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;">
General 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>
]]>