PDL::Tips 2.4.3

PDL::Tips is a Perl module with small tidbits of useful arcana. Programming tidbits and such.

SYNOPSIS
use PDL;

# Whatever happens here.

This page documents useful idioms, helpful hints and tips for using Perl Data Language v2.0.

Help

Use help help within perldl or the pdldoc program from the command line for access to the PerlDL documentation. HTML versions of the pages should also be present, in the HtmlDocs/PDL directory of the PDL distribution. To find this directory, try the following

perldl> foreach ( map{"$_/PDL/HtmlDocs"}@INC ) { p "$_n" if -d $_ }

Indexing idioms

The following code normalizes a bunch of vectors in $a. This works regardless of the dimensionality of $a.

$a /= $a->sumover->dummy(0);

What is actually happening?

If you want to see what the code is actually doing, try the command

PDL::Core::set_debugging(1);

somewhere. This spews out a huge amount of debug info for PDL into STDOUT. It is planned to eventually make this redirectable and the messages selectable more accurately.

Many of the messages come from Basic/Core/pdlapi.c and you can look at the source to see what is going on.

If you have any extra time to work on these mechanisms, infrom the pdl-porters mailing list.