/usr/local/CPAN/PDL/PDL/Demos/PGPLOT_OO_demo.pm

• package PDL::Demos::PGPLOT_OO_demo
  • run
• EOF

package PDL::Demos::PGPLOT_OO_demo;

# show how to use the new OO PGPLOT interface

use PDL;
use PDL::Graphics::PGPLOT::Window;

PDL::Demos::Routines->import();
sub comment($);
sub act($);
sub output;

sub run {

$ENV{PGPLOT_XW_WIDTH}=0.3;
$ENV{PGPLOT_DEV}=$^O =~ /MSWin32/ ? '/GW' : "/XSERVE";

comment q|
        The PGPLOT demo showed you how to use the old interface to PGPLOT.
        As this is perl, TIMTOWTDI, and this demo shows you how to use the
        new, object-orientated PGPLOT interface. For the simple examples
        shown here, the new method appears overkill; however, it really
        comes into its own when you wish to deal with multiple plots
        or windows.

        Enough prattle, on with the show...

|;

act q|
        # we start with a different module to the traditional interface
        use PDL::Graphics::PGPLOT::Window;

        # create a window "object"
        $dev = $^O =~ /MSWin32/ ? '/GW' : '/XSERVE';
        $win = PDL::Graphics::PGPLOT::Window->new( { Dev => $dev } );

|;

act q|
        # First we define some variables to use for the rest of the demo.
        $x=sequence(10);
        $y=2*$x**2;

        # Now a simple plot with points
        $win->points( $x, $y );

|;

act q|
        # Here is the same with lines
        $win->line( $x, $y );

        # if you're beginning to think its the same as the old calls, 
        # just with "$win->" at the beginning then you're not far wrong!

|;

act q|
        # You can do all the things you did before ...

        $win->points( $x, $y, {Symbol=>4} );
        $win->hold;
        $win->line( $x, $y );
        $yerr=sqrt($y);
        $win->errb( $x, $y, $yerr );

        $win->release;

|;

act q|
        # and it acts the same way

        $gradient=sequence(40,40);
        $win->imag( $gradient );
        $win->hold;
        $win->cont( $gradient );
        $win->release;

        # add labels to the plot
        $win->label_axes( "An axis", "Another axis", "Title" );
|;


act q|
    # let's try and read the cursor

    use PDL::Complex;
    $c =  zeroes(300)->xlinvals(0,12)+i*zeroes(300)->xlinvals(2,10);
    $sin = sin $c;
    $win->line( $sin->im, $sin->re );

    print "Select a point in the graph (mouse button or key press):\n";
    ( $x, $y, $ch ) = $win->cursor( { Type=>'CrossHair' } );
    
    print "\nYou selected: $x + $y i  (key = $ch)\n";

|;

# should really do something related to the selected points...

act q|
    # how about another window?

    $win2 = PDL::Graphics::PGPLOT::Window->new( { Dev => $dev } );
    $win2->env( 0, 4, -2, 0, { Axis => 'logy' } );
    $x = sequence(101) / 25;
    $win2->points( $x, $x->sin->abs()->log10 );

|;

act q|
    # switch back to the original window (we don't want to hurt
    # its feelings)

    $win->line( $x, { Border => 1 } );

|;

act q|
    # free up the windows, after finding their names

    print "You've been watching " . $win->name();
    print " and " . $win2->name() . "\n";

    $win->close();
    $win2->close();
        
|;

}

1;