Online Developer Meeting (2021-03-23)

• Date: Tuesday, March 23, 2021 @ 18:00 UTC
• Location: https://meet.jit.si/octave-dev-2021-03-23

Todays topics

• Meet and greet 5 minutes before meeting (audio testing).

Octave 7

Previous idea collections for Octave 7

• Category:Development#Goals_for_upcoming_releases
  • JWE Project Ideas
  • GUI terminal widget
• Discourse https://octave.discourse.group/t/goals-for-the-next-release/358
  • https://octave.discourse.group/t/new-command-window-widget/501

How to make Octave 7 visibly special?

• Implement Matlabs new String-class
  • Difficult, but highly demanded.
• Builtin hash-operator
  • Distinct feature from Matlab

Improve graphics

• Use "new" OpenGL code path
  • Nice overview by User:Hg200
  • Likely to make plotting faster (more efficient methods to move data to graphics card)
  • Does not solve "double precision" problem, scaling must happen on Octave side even with new OpenGL code path
• Consult professional OpenGL developer to review code
  • General agreement to spend Octave project money on this

Implement Matlabs new input validation

• jwe can create dummy tree-elements
  • Problem if values are evaluated, the "right" action must be done
• Can those validation statements come at arbitrary positions or only at the beginning of the file?

Command Window Widget

• GUI terminal widget, https://octave.discourse.group/t/new-command-window-widget/501 (jwe's patch!)
• Of special interest for MS Windows users
• Unify widget for all OSes
• Make jwe's patch a configurable options for testing (nothing to use productively yet)
• Need to implement own pager (alternatively: scroll bar only)
• Better responsibility delegation between GUI and interpreter
  • Big matrix output: interpreter could ask GUI to print big matrix, GUI could confirm with user, etc.
  • Formatting (colors, URLs, etc.) could be done by the GUI. Interpreter does not need to know about window-width, etc.

Backend code improvements

• "Ditch" old UNIX system functions (e.g. popen)
  • Move to package?
  • compose a list of functions that are candidates for removal from core Octave. See: Moving POSIX system call and library functions out of core Octave
• performance of symbol lookup
  • use std::unordered_map, rather than std::map to increase performance (e.g. of interpreter lookups)
  • Potentially implement "import" keyword? That would probably slow down symbol lookup some more.
• Replace custom reference counters with implementation using std::shared_ptr
  • Some instances are more difficult to replace. jwe will post something about this on the discourse forum.
• favor C++ std-library functions over gnulib where possible
  • Maybe require C++14 or C++17? See: Using C++17 features
• improve HDF5 integration
  • Add "wrapper" for libhdf5 functions in Octave's scripting language.
  • Key to support latest Matlab file formats. Try to implement in the interfaces for that format in .m file functions.
  • Some developers very interested in this!

Testing Matlab code

• jwe will a single Discourse thread to ask for tests in Matlab
  • Old Discourse threads many maintainers receive notifications.

Octave online service

• Similar to Matlab online
• There are already existing services
  • https://cocalc.com/doc/octave.html
  • https://octave-online.net/
• In general Jupyter-Notebook based solutions are already highly developed
• Running an own service lacks of manpower and financial resources

Documentation

• Split Octave manual https://octave.org/doc/latest into
  • Function reference, like Octave Forge https://octave.sourceforge.io/docs.php
    • Need knowledge how it was created (Kai looks at this again)
    • Once succeeded, hosted at https://octave.org/doc/
  • Usage manual (like the current one, more detailed, without @docstrings)

Ideas for next meeting

• Automatically reschedule the meeting monthly (Kai suggests on Discourse)
• MXE Octave branches and buildbots
• Strategy for transition to string class syntax (incompatible to current double-quoted character vectors in Octave)?
• Allow using more modern C++ dialects (C++17 STL std::filesystem or boost::filesystem)?

See also

• Next meeting: Online Developer Meeting (2021-04-27)
• Last meeting: Online Developer Meeting (2020-11-10)