Continuous Contour Coloring

perldemo\smoothcontour.pl
#!/usr/bin/perl

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

use perlchartdir;

# The x and y coordinates of the grid
my $dataX = [-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
my $dataY = [-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

# The values at the grid points. In this example, we will compute the values using the formula z =
# Sin(x / 2) * Sin(y / 2).
my $dataZ = [(0) x (scalar(@$dataX) * scalar(@$dataY))];
for(my $yIndex = 0; $yIndex < scalar(@$dataY); ++$yIndex) {
    my $y = $dataY->[$yIndex];
    for(my $xIndex = 0; $xIndex < scalar(@$dataX); ++$xIndex) {
        my $x = $dataX->[$xIndex];
        $dataZ->[$yIndex * scalar(@$dataX) + $xIndex] = sin($x / 2.0) * sin($y / 2.0);
    }
}

# Create a XYChart object of size 600 x 500 pixels
my $c = new XYChart(600, 500);

# Add a title to the chart using 18 points Times New Roman Bold Italic font
$c->addTitle("Nano Lattice Twister Field Intensity        ", "Times New Roman Bold Italic", 18);

# Set the plotarea at (75, 40) and of size 400 x 400 pixels. Use semi-transparent black (80000000)
# dotted lines for both horizontal and vertical grid lines
$c->setPlotArea(75, 40, 400, 400, -1, -1, -1, $c->dashLineColor(0x80000000, $perlchartdir::DotLine),
    -1);

# Set x-axis and y-axis title using 12 points Arial Bold Italic font
$c->xAxis()->setTitle("Lattice X Direction (nm)", "Arial Bold Italic", 12);
$c->yAxis()->setTitle("Lattice Y Direction (nm)", "Arial Bold Italic", 12);

# Set x-axis and y-axis labels to use Arial Bold font
$c->xAxis()->setLabelStyle("Arial Bold");
$c->yAxis()->setLabelStyle("Arial Bold");

# When auto-scaling, use tick spacing of 40 pixels as a guideline
$c->yAxis()->setTickDensity(40);
$c->xAxis()->setTickDensity(40);

# Add a contour layer using the given data
my $layer = $c->addContourLayer($dataX, $dataY, $dataZ);

# Set the contour color to transparent
$layer->setContourColor($perlchartdir::Transparent);

# Move the grid lines in front of the contour layer
$c->getPlotArea()->moveGridBefore($layer);

# Add a color axis (the legend) in which the left center point is anchored at (495, 240). Set the
# length to 370 pixels and the labels on the right side.
my $cAxis = $layer->setColorAxis(495, 240, $perlchartdir::Left, 370, $perlchartdir::Right);

# Add a bounding box to the color axis using light grey (eeeeee) as the background and dark grey
# (444444) as the border.
$cAxis->setBoundingBox(0xeeeeee, 0x444444);

# Add a title to the color axis using 12 points Arial Bold Italic font
$cAxis->setTitle("Twist Pressure (Twist-Volt)", "Arial Bold Italic", 12);

# Set color axis labels to use Arial Bold font
$cAxis->setLabelStyle("Arial Bold");

# Use smooth gradient coloring
$cAxis->setColorGradient(1);

# Output the chart
$c->makeChart("smoothcontour.jpg");