Summer of Code - Getting Started: Difference between revisions

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Summer of Code - Getting Started (edit)

Revision as of 11:00, 26 January 2023

316 bytes added ,  26 January 2023
→‎Improve TIFF image support: removed (done in GSoC 2022)
(→‎openlibm: Add great list by User:Shreyaswikriti 🙂👍)
(→‎Improve TIFF image support: removed (done in GSoC 2022))
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{{Note|GNU Octave is a [https://summerofcode.withgoogle.com/programs/2022/organizations/gnu-octave mentoring organization for GSoC 2022].}}
{{Note|GNU Octave is applying to be a [https://summerofcode.withgoogle.com/programs/2023/organizations/gnu-octave mentoring organization for GSoC 2023].}}


Since 2011 the GNU Octave project has successfully mentored:
Since 2011 the GNU Octave project has successfully mentored:
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{{Note|Do you use Octave at your working place or university? Do you have some numerical project in mind?  You are always welcome to '''propose your own projects'''.  If you are passionate about your project, it will be easy to find an Octave developer to mentor and guide you.}}
{{Note|Do you use Octave at your working place or university? Do you have some numerical project in mind?  You are always welcome to '''propose your own projects'''.  If you are passionate about your project, it will be easy to find an Octave developer to mentor and guide you.}}
== openlibm ==
Over the years Octave faced many issues (see [[openlibm | the openlibm page in this wiki]] for examples) about different [https://en.wikipedia.org/wiki/C_mathematical_functions#libm C mathematical functions library] (in short: "libm") implementations on various systems.  To overcome similar issues, developers of the [https://en.wikipedia.org/wiki/Julia_(programming_language) Julia Programming Language] started the [https://openlibm.org/ openlibm] project "to have a good libm [ ...] that work[s] consistently across compilers and operating systems, and in 32-bit and 64-bit environments".  openlibm is supported by major Linux distributions (e.g. [https://packages.ubuntu.com/focal/libopenlibm-dev Debian/Ubuntu], [https://src.fedoraproject.org/rpms/openlibm RHEL/Fedora],[https://software.opensuse.org/package/openlibm SLES/openSUSE], ...) and the [https://hg.octave.org/mxe-octave/rev/480f60641fc2 MS Windows MXE package] was added as well.
This project consists of learning about the usage of [https://en.wikipedia.org/wiki/GNU_Autotools GNU Autotools] in Octave and ways to detect openlibm.  As the next step the Octave code base has to be reviewed under the guidance of a mentor and relevant code changes should be performed.  Finally, relevant code changes in the [[Tests | Octave test suite]] are performed and tested on various Linux, MS Windows, and macOS machines with the help of the Octave community.
* '''Project size''' [[#Project sizes | [?]]] and '''Difficulty'''
: ~175 hours (easy)
* '''Required skills'''
: Octave, C/C++, Autotools
* '''Potential mentors'''
: [https://octave.discourse.group/u/cdf Carlo de Falco], [https://octave.discourse.group/u/siko1056 Kai]


== ode15{i,s} : Matlab Compatible DAE solvers ==
== ode15{i,s} : Matlab Compatible DAE solvers ==
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was done by [https://gsoc2016ode15s.blogspot.com/ Francesco Faccio during GSoC 2016].  The code is maintained in the main Octave repository and consists mainly of the following three files: [https://hg.savannah.gnu.org/hgweb/octave/file/tip/libinterp/dldfcn/__ode15__.cc {{path|libinterp/dldfcn/__ode15__.cc}}], [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/ode/ode15i.m {{path|scripts/ode/ode15i.m}}] and [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/ode/ode15s.m {{path|scripts/ode/ode15s.m}}].
was done by [https://gsoc2016ode15s.blogspot.com/ Francesco Faccio during GSoC 2016].  The code is maintained in the main Octave repository and consists mainly of the following three files: [https://hg.savannah.gnu.org/hgweb/octave/file/tip/libinterp/dldfcn/__ode15__.cc {{path|libinterp/dldfcn/__ode15__.cc}}], [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/ode/ode15i.m {{path|scripts/ode/ode15i.m}}] and [https://hg.savannah.gnu.org/hgweb/octave/file/tip/scripts/ode/ode15s.m {{path|scripts/ode/ode15s.m}}].


The {{manual|decic}} function for selecting consistent initial conditions for ode15i can be made more Matlab compatible by using [https://faculty.smu.edu/shampine/cic.pdf another algorithm].  Another useful extension is to make ode15{i,s} work with datatypes other than double and to improve interpolation at intermediate time steps.
The {{manual|decic}} function for selecting consistent initial conditions for ode15i can be made more Matlab compatible by using [http://dx.doi.org/10.1515/JNMA.2002.291 another algorithm].  Another useful extension is to make ode15{i,s} work with datatypes other than double and to improve interpolation at intermediate time steps.


* '''Project size''' [[#Project sizes | [?]]] and '''Difficulty'''
* '''Project size''' [[#Project sizes | [?]]] and '''Difficulty'''
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: Francesco Faccio, [https://octave.discourse.group/u/cdf Carlo de Falco], [https://octave.discourse.group/u/marco_caliari Marco Caliari], Jacopo Corno, [https://octave.discourse.group/u/schoeps Sebastian Schöps]
: Francesco Faccio, [https://octave.discourse.group/u/cdf Carlo de Falco], [https://octave.discourse.group/u/marco_caliari Marco Caliari], Jacopo Corno, [https://octave.discourse.group/u/schoeps Sebastian Schöps]


== Improve TIFF image support ==
== Symbolic package ==
 
[https://en.wikipedia.org/wiki/TIFF Tag Image File Format (TIFF)] is the de facto standard for scientific images.  Octave uses the [http://www.graphicsmagick.org/ GraphicsMagic] (GM) C++ library to handle [http://www.graphicsmagick.org/formats.html TIFF and many others image formats]. However, GM still has several limitations:
 
* GM has build option {{codeline|quantum}} which defines the bitdepth to use when reading an image:
** Building GM with '''high quantum''' means that images of smaller bitdepth will take a lot more memory when reading.
** Building GM with '''low quantum''' will make it impossible to read images of higher bitdepth. It also means that the image needs to always be rescaled to the correct range.
* GM supports unsigned integers only, thus incorrectly reading files such as TIFF with floating-point data.
* GM hides details of the image such as whether the image file is indexed.  This makes it hard to access the real data stored on file.


This project aims to implement better TIFF image support using [https://en.wikipedia.org/wiki/Libtiff libtiff], while leaving GM handle all other image formats.  After writing a [https://octave.org/doc/v6.1.0/classdef-Classes.html classdef] interface to libtiff, improve the Octave functions {{manual|imread}}, {{manual|imwrite}}, and {{manual|imfinfo}} to make use of it.
The [[Symbolic package]] provides symbolic computing and other [https://en.wikipedia.org/wiki/Computer_algebra_system computer algebra system] tools.  The main component of Symbolic is a pure m-file class "@sym" which uses the Python package [https://www.sympy.org SymPy] to do (most of) the actual computations.  The package aims to expose much of the functionality of SymPy while also providing a high level of compatibility with the Matlab Symbolic Math Toolbox. The Symbolic package requires communication between Octave and Python. In 2016 a GSoC project successfully re-implemented this communication using the new [[Pythonic|Pythonic package]].  In 2022, a GSoC project revitalized and improved the maintainability of the package.


* '''Project size''' [[#Project sizes | [?]]] and '''Difficulty'''
Possible ideas for improving the Symbolic package:
: ~350 hours (medium)
* exposing more functionality of SymPy with ''less glue'' in between.  For example, we could allow OO-style method calls such as <code>f.diff(x)</code> as well as <code>diff(f, x)</code>.
* '''Required skills'''
* Fix the storage of non-expressions by working with upstream SymPy: currently we rely on deprecated functionality in SymPy.
: Octave, C/C++
* Fix classdef-related issues in Octave itself.
* '''Potential mentors'''
: [https://octave.discourse.group/u/carandraug Carnë Draug]


== PolarAxes and Plotting Improvements ==
== PolarAxes and Plotting Improvements ==
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* '''Project size''' [[#Project sizes | [?]]] and '''Difficulty'''
* '''Project size''' [[#Project sizes | [?]]] and '''Difficulty'''
: ~350 hours (easy)
: ~175 hours (easy)
* '''Required skills'''
* '''Required skills'''
: Octave, C/C++
: Octave, C/C++
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* '''Potential mentors'''
* '''Potential mentors'''
: [https://octave.discourse.group/u/kakila KaKiLa]
: [https://octave.discourse.group/u/kakila KaKiLa]
== Better tab completion ==
Links: [https://savannah.gnu.org/bugs/index.php?62492 https://savannah.gnu.org/bugs/index.php?62492] and [https://savannah.gnu.org/bugs/?53384 https://savannah.gnu.org/bugs/?53384]
Description: currently pressing Tab at the Octave command prompt attempts autocompletion of all identifiers in scope (variables, functions, classdefs etc) as well as files and directories in the path. It is not context sensitive.
Project: Improve tab completion. For example,
* Typing
: load x
and then pressing tab should ideally give all loadable files and directories starting with x, not unrelated results like variables or functions.
* Typing
:cd
and tab should only give directories.
* Any file and directory names that are included in the results should include those with spaces and special characters including those that would be interpreted as operators by Octave.
* Typing commands like
: axis
or
: format
and pressing tab should give only those options relevant to that command. E.g. format can be followed by short / long / loose / compact etc but not by a file or variable. Similarly axis can be followed by ij / xy / tight / equal / actual limits etc but not by files or directories. And so on for other commands. This should be made possible for both preexisting commands and for yet-to-be-written commands without any rewriting of existing function code or documentation.
To get more examples, see how bash completion works. You can type git or hg and then tab and it will give the list of available commands. If you type "sort --r" and then tab, it gives the list of options to sort starting with "--r", etc.
== Graphics rendering back to front sorting ==
Several incompatibilities have been identified in how Octave plots transparent objects in 3D, causing certain transparent objects to hide opaque objects behind them even though they're not supposed to. The vast majority of them were isolated to one problem: if the objects to be drawn are rendered such that the one farthest away from the viewer is rendered first and nearer objects are rendered on top of that, then transparency would be automatically achieved, but this needs very careful coding to stay performant and to avoid rendering objects that will be overwritten fully by others. See [https://savannah.gnu.org/bugs/?57980] for a summary.
This project can be a GSoC for a student who understands 3D graphics rendering.


= Project sizes =
= Project sizes =
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