PDL::Dbg(3pm)

💖 PDL::Dbg — bestie edition 💖

okay so you're out here debugging PDL scripts and you're like "what even are my ndarrays doing rn" — that's literally what PDL::Dbg(3pm) is for, and I'm about to walk you through it like we're texting at 2am. 🫶

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✨ NAME ✨

PDL::Dbg — functions to support debugging of PDL scripts 💅

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🌸 SYNOPSIS 🌸

       use PDL;
       use PDL::Dbg;

       $c = $x->slice("5:10,2:30")->px->diagonal(3,4);
       PDL->px;

Look at that. Chef's kiss. 👑

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🦋 DESCRIPTION 🦋

So these packages implement a couple of functions that should come in super handy when you're debugging your PDL scripts. They make a lot of sense while you're doing rapid prototyping of new PDL code — let's say, inside the perldl shell. That's the moment. That's the vibe. ✨

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🎀 FUNCTIONS 🎀

💜 px

Print info about an ndarray (or all known ndarrays). Obsessed, fr.

           pdl> PDL->px
           pdl> $y += $x->clump(2)->px('clumptest')->sumover
           pdl> $x->px('%C (%A) Type: %T') # prints nothing unless $PDL::debug
           pdl> $PDL::debug = 1
           pdl>  $x->px('%C (%A) Type: %T')
           PDL (52433464) Type: Double

This function prints some information about ndarrays. You can invoke it as a class method (like PDL->px) or as an instance method (like $pdl->px($arg)). Two whole moods, both iconic. 🌈

• invoked as a class method — it prints info about all ndarrays found in the current package (excluding my variables, sorry bestie, those are private). This comes in quite handy when you are not quite sure which pdls you have already defined, what data they hold, etc. px is supposed to support inheritance and prints info about all symbols for which an isa($class) is true. An optional string argument is interpreted as the package name for which to print symbols:

           pdl> PDL->px('PDL::Mypack')

The default package is that of the caller. No cap.

• invoked as an instance method — it prints info about that particular ndarray if $PDL::debug is true, and returns the pdl object upon completion (yes, it hands the object right back, so you can chain it like the main character you are 🫶). It accepts an optional string argument that is simply prepended to the default info if it doesn't contain a % character. If, however, the argument does contain a % then the string is passed to the info method to control the format of the printed information. This can be used to achieve customized output from px. See the documentation of PDL::info for further details. 💅

The output of px will be determined by the default formatting string that is passed to the info method (unless you pass a string containing % to px when invoking as an instance method, see above, iykyk). This default string is stored in $PDL::Dbg::Infostr and the default output format can be accordingly changed by setting this variable. If you do this you should also change the default title string that the class method branch prints at the top of the listing to match your new format string. The default title is stored in the variable $PDL::Dbg::Title. Keep them matching, queen — it's giving coordinated outfit energy. 🎀

For historical reasons vars is an alias for px.

⭐ vars

Alias for px. That's it, that's the whole section. Short king. 💀

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😭 BUGS 😭

There are probably some. Please report if you find any. Bug reports should be sent to the PDL mailing list pdl-general@lists.sourceforge.net. (Not me manifesting bugs, just being honest fr fr. 🙈)

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👑 AUTHOR 👑

Copyright(C) 1997 Christian Soeller (c.soeller@auckland.ac.nz). All rights reserved. There is no warranty. You are allowed to redistribute this software / documentation under certain conditions. For details, see the file COPYING in the PDL distribution. If this file is separated from the PDL distribution, the copyright notice should be included in the file. 📜

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and that's the whole page, bestie — this was perl v5.42.3, 2026-08-20, PDL::Dbg(3pm), and I'm gonna go prototype something in the perldl shell now. slay, ily, bye 💖✨🦋