PDL::DeveloperGuide - Man Page

How to develop for PDL

Public Git Repository

The PDL source distribution is hosted with "Git" at the GitHub site <https://github.com/PDLPorters/pdl>, alongside with other PDL related software.

This is the preferred place to submit bug reports or, even better, pull requests.

Make sure you add a test case in the 't' directory for any significant additional capability you add to PDL. Please use Test::More or one the of the Test modules available via perl modules rather than doing-it-yourself!

3) Add documentation

Please include POD documentation for any functions you add to the distribution.

4) Run the tests

Don't commit before you successfully built and passed make test.

5) Watch for bug reports

Bugs should be reported to the GitHub issue tracker at <https://github.com/PDLPorters/pdl/issues>. See PDL::Bugs for a detailed description.

6) PDL Developer Recommended Workflow

This is detailed in section 4.11 of PDL::FAQ.

PDL Developer Notes

Getting (some) Debug Information

PDL has some global variables which control diagnostic output:

$::PP_VERBOSE: If set to a true value, PDL::PP will print details while building the module processing pp_def declarations.
$PDL::Graphics::TriD::verbose: If set to a true value, the routines in PDL::Graphics::TriD will report their progress.
$PDL::verbose: Several modules produce diagnostic output to STDOUT if $PDL::verbose has a true value.
$PDL::debug: Several modules produce diagnostic output if $PDL::verbose has a true value.

Generating a Stack Trace

To generate a stack-trace to help us debug a problem, please first of all do make realclean, ensure you have the latest released PDL. Then, if it is still happening, please follow this process:

Rerun perl Makefile.PL: This will update the timestamps on Makefiles, prompting a full rebuild.
Edit your generated top-level Makefile: Add -g to the OPTIMIZE = line to generate debug symbols (this gets propagated to subdirectories)
Run: make: This builds PDL into the blib directory.
Run: gdb perl -ex 'run -Mblib t/tracking.t': In gdb, run: bt
Copy-paste the backtrace output: This should show where the segfault originated.

Then please open an issue on whichever repo is relevant with your perl -V output and PDL version, together with the stack-trace created above. When you do paste such output into a GitHub issue, please surround such blocks with ``` on their own lines. You can check out how it will render with the "Preview" button above the issue-editing box.

Random Musings

A (small) collection of random musings to note if you feel the need to improve or add to PDL (please do):

Organizing Commits: The preferred way to organize commits is one commit per small, meaningful change (ideally each with an update to the corresponding tests). This makes it easy in the log to determine what was done and to locate any desired commit in case of issues that need to be resolved.

Finding the Source

The directory layout in the repository is different from the layout of a PDL installation. For some modules the .pm files are generated via PDL::PP, so changes would need to go into their .pd sources. Here's a table mapping PDL package names to their origin:

  | Package                                | Source file                     |
  |----------------------------------------+---------------------------------|
  | PDL                                    | Basic/PDL.pm                    |
  | PDL::Bad                               | Basic/Bad/bad.pd                |
  | PDL::Basic                             | Basic/Core/Basic.pm             |
  | PDL::Core                              | Basic/Core/Core.pm              |
  | PDL::Demos                             | Demos/Demos.pm                  |
  | PDL::Graphics::TriD                    | Graphics/TriD/TriD.pm           |
  | PDL::Graphics::TriD::*                 | Graphics/TriD/Objects.pm        |
  | PDL::Graphics::TriD::BoundingBox       | Graphics/TriD/TriD.pm           |
  | PDL::Graphics::TriD::Material          | Graphics/TriD/TriD.pm           |
  | PDL::Graphics::TriD::OneTransformation | Graphics/TriD/TriD.pm           |
  | PDL::Graphics::TriD::QuaterController  | Graphics/TriD/TriD/ArcBall.pm   |
  | PDL::Graphics::TriD::Scale             | Graphics/TriD/TriD.pm           |
  | PDL::Graphics::TriD::Transformation    | Graphics/TriD/TriD.pm           |
  | PDL::Graphics::TriD::Translation       | Graphics/TriD/TriD.pm           |
  | PDL::IO::FITS                          | IO/FITS/FITS.pm                 |
  | PDL::IO::Misc                          | IO/Misc/misc.pd                 |
  | PDL::IO::Pic                           | IO/Pnm/pnm.pd                   |
  | PDL::IO::Storable                      | IO/Storable/storable.pd         |
  | PDL::Lvalue                            | Basic/Lvalue.pm                 |
  | PDL::Math                              | Basic/Math/math.pd              |
  | PDL::MatrixOps                         | Basic/MatrixOps/matrixops.pd    |
  | PDL::NiceSlice                         | Basic/SourceFilter/NiceSlice.pm |
  | PDL::Ops                               | Basic/Ops/ops.pd                |
  | PDL::Primitive                         | Basic/Primitive/primitive.pd    |
  | PDL::Slices                            | Basic/Slices/slices.pd          |
  | PDL::Ufunc                             | Basic/Ufunc/ufunc.pd            |