ChartDirector 6.0 (Perl Edition)

Log Scale Axis


  

This example demonstrates using a log scale axis versus a linear scale axis.

In ChartDirector, log scale axis can be configured using Axis.setLogScale, Axis.setLogScale2 or Axis.setLogScale3.

Source Code Listing

[Standalone Version] perldemo\logaxis.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;

sub createChart
{
    my $chartIndex = shift;

    # The data for the chart
    my $data = [100, 125, 260, 147, 67];
    my $labels = ["Mon", "Tue", "Wed", "Thu", "Fri"];

    # Create a XYChart object of size 200 x 180 pixels
    my $c = new XYChart(200, 180);

    # Set the plot area at (30, 10) and of size 140 x 130 pixels
    $c->setPlotArea(30, 10, 140, 130);

    # Ise log scale axis if required
    if ($chartIndex == 1) {
        $c->yAxis()->setLogScale3();
    }

    # Set the labels on the x axis
    $c->xAxis()->setLabels($labels);

    # Add a color bar layer using the given data. Use a 1 pixel 3D border for the bars.
    $c->addBarLayer3($data)->setBorderColor(-1, 1);

    # Output the chart
    $c->makeChart("logaxis$chartIndex.png")
}

createChart(0);
createChart(1);

[CGI Version] perldemo_cgi\logaxis.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;

# Get HTTP query parameters
use CGI;
my $query = new CGI;

# This script can draw different charts depending on the chartIndex
$chartIndex = int($query->param("img"));

# The data for the chart
my $data = [100, 125, 260, 147, 67];
my $labels = ["Mon", "Tue", "Wed", "Thu", "Fri"];

# Create a XYChart object of size 200 x 180 pixels
my $c = new XYChart(200, 180);

# Set the plot area at (30, 10) and of size 140 x 130 pixels
$c->setPlotArea(30, 10, 140, 130);

# Ise log scale axis if required
if ($chartIndex == 1) {
    $c->yAxis()->setLogScale3();
}

# Set the labels on the x axis
$c->xAxis()->setLabels($labels);

# Add a color bar layer using the given data. Use a 1 pixel 3D border for the bars.
$c->addBarLayer3($data)->setBorderColor(-1, 1);

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