ChartDirector 6.0 (Perl 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

[Standalone Version] perldemo\paramcurve.pl
#!/usr/bin/perl

# In the sample code, the ChartDirector for Perl module is assumed to be in "../lib"
use File::Basename;
use lib (dirname($0)."/../lib") =~ /(.*)/;

use perlchartdir;

# The XY data of the first data series
my $dataX0 = [10, 35, 17, 4, 22, 29, 45, 52, 63, 39];
my $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
my $dataX1 = [30, 35, 17, 4, 22, 59, 43, 52, 63, 39];
my $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
my $dataX2 = [28, 35, 15, 10, 22, 60, 46, 64, 39];
my $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
my $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.
my $legendBox = $c->addLegend(270, 30, 0, "arialbi.ttf", 10);
$legendBox->setAlignment($perlchartdir::TopCenter);
$legendBox->setBackground($perlchartdir::Transparent, $perlchartdir::Transparent);

# Add a title to the chart using 18 point Times Bold Itatic font.
$c->addTitle("Parametric Curve Fitting", "timesbi.ttf", 18);

# Add titles to the axes using 12pt Arial Bold Italic font
$c->yAxis()->setTitle("Axis Title Placeholder", "arialbi.ttf", 12);
$c->xAxis()->setTitle("Axis Title Placeholder", "arialbi.ttf", 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", $perlchartdir::GlassSphere2Shape, 11, 0xff0000);

# Add a degree 2 polynomial trend line layer for (dataX0, dataY0)
my $trend0 = $c->addTrendLayer2($dataX0, $dataY0, 0xff0000);
$trend0->setLineWidth(3);
$trend0->setRegressionType(perlchartdir::PolynomialRegression(2));

# Add a scatter layer for (dataX1, dataY1)
$c->addScatterLayer($dataX1, $dataY1, "Exponential", $perlchartdir::GlassSphere2Shape, 11, 0x00aa00)
    ;

# Add an exponential trend line layer for (dataX1, dataY1)
my $trend1 = $c->addTrendLayer2($dataX1, $dataY1, 0x00aa00);
$trend1->setLineWidth(3);
$trend1->setRegressionType($perlchartdir::ExponentialRegression);

# Add a scatter layer using (dataX2, dataY2)
$c->addScatterLayer($dataX2, $dataY2, "Logarithmic", $perlchartdir::GlassSphere2Shape, 11, 0x0000ff)
    ;

# Add a logarithmic trend line layer for (dataX2, dataY2)
my $trend2 = $c->addTrendLayer2($dataX2, $dataY2, 0x0000ff);
$trend2->setLineWidth(3);
$trend2->setRegressionType($perlchartdir::LogarithmicRegression);

# Output the chart
$c->makeChart("paramcurve.png")

[CGI Version] perldemo_cgi\paramcurve.pl
#!/usr/bin/perl

# In the sample code, the ChartDirector for Perl module is assumed to be in "../lib"
use File::Basename;
use lib (dirname($0)."/../lib") =~ /(.*)/;

use perlchartdir;

# The XY data of the first data series
my $dataX0 = [10, 35, 17, 4, 22, 29, 45, 52, 63, 39];
my $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
my $dataX1 = [30, 35, 17, 4, 22, 59, 43, 52, 63, 39];
my $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
my $dataX2 = [28, 35, 15, 10, 22, 60, 46, 64, 39];
my $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
my $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.
my $legendBox = $c->addLegend(270, 30, 0, "arialbi.ttf", 10);
$legendBox->setAlignment($perlchartdir::TopCenter);
$legendBox->setBackground($perlchartdir::Transparent, $perlchartdir::Transparent);

# Add a title to the chart using 18 point Times Bold Itatic font.
$c->addTitle("Parametric Curve Fitting", "timesbi.ttf", 18);

# Add titles to the axes using 12pt Arial Bold Italic font
$c->yAxis()->setTitle("Axis Title Placeholder", "arialbi.ttf", 12);
$c->xAxis()->setTitle("Axis Title Placeholder", "arialbi.ttf", 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", $perlchartdir::GlassSphere2Shape, 11, 0xff0000);

# Add a degree 2 polynomial trend line layer for (dataX0, dataY0)
my $trend0 = $c->addTrendLayer2($dataX0, $dataY0, 0xff0000);
$trend0->setLineWidth(3);
$trend0->setRegressionType(perlchartdir::PolynomialRegression(2));

# Add a scatter layer for (dataX1, dataY1)
$c->addScatterLayer($dataX1, $dataY1, "Exponential", $perlchartdir::GlassSphere2Shape, 11, 0x00aa00)
    ;

# Add an exponential trend line layer for (dataX1, dataY1)
my $trend1 = $c->addTrendLayer2($dataX1, $dataY1, 0x00aa00);
$trend1->setLineWidth(3);
$trend1->setRegressionType($perlchartdir::ExponentialRegression);

# Add a scatter layer using (dataX2, dataY2)
$c->addScatterLayer($dataX2, $dataY2, "Logarithmic", $perlchartdir::GlassSphere2Shape, 11, 0x0000ff)
    ;

# Add a logarithmic trend line layer for (dataX2, dataY2)
my $trend2 = $c->addTrendLayer2($dataX2, $dataY2, 0x0000ff);
$trend2->setLineWidth(3);
$trend2->setRegressionType($perlchartdir::LogarithmicRegression);

# Output the chart
binmode(STDOUT);
print "Content-type: image/png\n\n";
print $c->makeChart2($perlchartdir::PNG);