Project - Documentation

This article contains project ideas related to improve GNU Octave's documentation. For general project ideas, see Projects.

News

• GNU Octave might apply for Google Season of Docs (GSoD) in 2023. Examples of successful projects from other organizations can be found at:
  • latest: GSoD Current Participants List
  • Past GSOD Participants and Projects: 2019 - 2020 - 2021 - 2022

• Discuss about your ideas and application with us by:
  • GNU Octave User and Developer Forum
  • IRC
  • updating this wiki page

Existing Documentation

For a comprehensive list see Publications about Octave.

• Texinfo user / developer documentation for the Octave interpreter.

• Doxygen documentation for the internal C++ classes and external API.

• This wiki:
  • FAQ
  • Resources: Tutorials, Examples, Tips and Tricks, ...

Suggested Projects

Octave's interpreter documentation

Description

The documentation for the interpreter is presumably the oldest, long grown documentation of the GNU Octave project. It is mostly written in Texinfo and strongly interleaved in the Octave build process, i.e., it is necessary to build Octave from source to generate included figures. Additionally, large portions of the Texinfo source are auto generated to stay close to the source code and to avoid stale documentation. A special type of this auto generation are the so-called "docstrings", which are extracted from both C++ files and Octave's own script files (m-files).

The resulting Texinfo sources are translated to Info, PDF, PostScript, and HTML, whereas the HTML is further processed to match the QT Help Framework, which is displayed in the Octave GUI.

Improvements

• Easy but long task: Every function description should mention the output variable if there is one. See bug #61681 and #Working list of functions needing output variables below.
• Check for inconsistencies in the manual, e.g., outdated descriptions, awkwardly ordered information, ...
• More examples and demo files for using each Octave command.
• More figures to demonstrate Octave's plotting capabilities, but regard doc size and building time.
• Think about a superior organization/splitting of the manual. Currently it covers many topics interleaved: user manual, function reference, developer guide.
  • Idea for a function reference including Octave Forge packages: https://octave.sourceforge.io/docs.php (unmaintained)
• Document the documentation building process (e.g. rename and document involved scripts).

Long term goals / highly controversial within the community

• Syntax, structure, and source-code readability of Texinfo is a burden for some developers and newcomers. In short it is no "fun" editing those. Consider replacement by
  • CommonMark/Markdown
  • reStructuredText / Sphinx
  • ...

Resources

• Style Guides

Contribution guidelines#Coding style

• Source code

https://hg.savannah.gnu.org/hgweb/octave/file/tip/doc/interpreter

• Required skills

Texinfo, hg, building Octave from source

• Potential mentors

Kai

Octave's internal documentation

Description

Since 2013, Octave makes use of Doxygen, and etc/HACKING.md for its internal documentation. There has been only moderate effort to add Doxygen comments to the entire code base or to create verbose descriptions for key techniques about how Octave works (here an example for important Octave macros). Potential reasons for this circumstance are:

1. Lack of developer knowledge (code grew over 25 years), many "cryptic" macros, very complex class inheritance trees:
   • liboctave/Array
   • libinterp/octave_base_value
2. long Doxygen build time to see results of documentation effort
3. huge size (about 2 GB), very impractical to "carry around", [1] slowly responding

Nevertheless, there is a need for internal documentation:

1. Comprehensive documentation of Octave's external code interface.
2. Enable newcomers (e.g. GSoC students) to study Octave's code easily.
3. Avoid knowledge drain (bus factor).

Improvements

• The internal documentation should cover the following topics (a more verbose extension of etc/HACKING.md (html)):
  • Overview about the code base (liboctave, libinterp, libgui, ...).
  • How Octave is built (necessary tools [versions], involved scripts, ...).
  • The release procedure, e.g. 6.1 Release Checklist.
• Make the internal documentation obvious, easy to study and to extend, avoid effort duplication.
  • The internal documentation should not be fixed on Doxygen comments only.
  • As Octave's GUI makes use of qt, Doxygen might also be replaced by QDoc with comparable markup.
  • Splitting the documentation into a wiki portion, etc., is imaginable, but it must be clearly documented where to find which information, avoid duplication, nobody wants to update information in more than one location.
• Technical goals are:
  • Smaller memory footprint for individual documents (unlike current Doxygen with about 2 GB).
  • Fast build time.
  • Lightweight (existing) documentation system. No heavy preprocessing / code generation by custom scripts.
  • As close to the source as necessary. Make it difficult to update the code while not updating its documentation. E.g. no wiki documentation for Octave's C++ files.

Resources

• Style Guides

C++ style guide#Doxygen

• Source code

https://hg.savannah.gnu.org/hgweb/octave/file/tip/doc/doxyhtml

• Required skills

Doxygen, hg, building Octave from source

• Potential mentors

Kai