Getting help, contributing and reporting problems
=================================================

Mailing list
------------

The mailing list is the main public communication platform for anything related
to Kwant: questions, bug reports, discussions, and announcements.  You can use
it in various ways:

- .. raw:: html

     <form method=post action="https://mailman-mail5.webfaction.com/subscribe/kwant-discuss">
     <input type="text" name="email" size=25 value="Your email address" onblur="if (this.value == '') {this.value='Your email address'}" onfocus="if (this.value == 'Your email address') {this.value=''}" />
     <input type="submit" name="email-button" value="Subscribe to the mailing list" />
     </form>

  … and read it together with your regular email.  (To unsubscribe, follow the
  link in the footer of a message.)

- Read the list via the `Gmane web interface
  <http://news.gmane.org/gmane.comp.science.kwant.user>`_.  The web interface
  allows to write new messages (action: post) and to reply (action: followup).

- .. raw:: html

      <p><form id="searchgmane" method="get" action="http://search.gmane.org/">
      <input type="text" size=25 name="query" />
      <input type="hidden" name="group" value="gmane.comp.science.kwant.user" />
      <input type="submit" value="Search the mailing list" />
      </form></p>

- Send a message directly to kwant-discuss@kwant-project.org.  (If you are not
  subscribed, it is not guaranteed that any followups will reach you by email,
  so you should ask to be CCed.)


Announcements of new releases (low-volume)
------------------------------------------

This read-only list is reserved for important announcements like new releases of
Kwant.  Only a few messages will be sent per year.  These announcements will be also posted on the main mailing list, so there is no need to subscribe to both lists.  We recommend every user of Kwant to subscribe at least to this list in order to stay informed about new developments.

.. raw:: html

   <form method=post action="https://mailman-mail5.webfaction.com/subscribe/kwant-announce">
   <input type="text" name="email" size=25 value="Your email address" onblur="if (this.value == '') {this.value='Your email address'}" onfocus="if (this.value == 'Your email address') {this.value=''}" />
   <input type="submit" name="email-button" value="Subscribe to announcements" />
   </form>


Reporting bugs
--------------

If you encounter a problem with Kwant, first try to reproduce it with as simple
a system as possible.  Double-check with the documentation that what you
observe is actually a bug in Kwant. If you think it is, please check whether
the problem is already known by searching the mailing list.

If the problem is not known yet, please send a bug report to the mailing list.
A report should contain:

* The versions of software you are using (Kwant, Python, operating system, etc.)

* A description of the problem, i.e. what exactly goes wrong.

* Enough information to reproduce the bug, preferably in the form of a simple
  script.


Contributing
------------

We see Kwant not just as a package with fixed functionality, but rather as a
framework for implementing different physics-related algorithms using a common
set of concepts and, if possible, a shared interface.  We have designed it
leaving room for growth, and plan to keep extending it.

External contributions to Kwant are highly welcome.  You can help to advance
the project not only by writing code, but also by reporting bugs, and
fixing/improving the documentation.  A `mailing list
</community.html>`_ is available for discussions.

If you have some code that works well with Kwant, or extends it in some useful
way, please consider sharing it.  Any external contribution will be clearly
marked as such, and relevant papers will be added to the list of `suggested
acknowledgements </citing.html>`_.  The complete development history is also
made available through a `web interface <http://git.kwant-project.org/kwant>`_.
If you plan to contribute, it is best to coordinate with us in advance either
through the mailing list, or directly at authors@kwant-project.org for matters
that you prefer to not discuss publicly.


How to contribute
.................

We use the version control system `Git <http://git-scm.com/>`_ to coordinate the
development of Kwant.  If you are new to Git, we invite you to learn its basics.
(There's a plethora of information available on the Web.)  Kwant's Git
repository contains not only the source code, but also all of the reference
documentation and the tutorial.

It is best to base your work on the latest version of Kwant::

    git clone http://git.kwant-project.org/kwant

Then you can modify the code, and build Kwant and the documentation as
described in the `build instructions
</doc/1.0/pre/install.html#building-and-installing-from-source>`_.

Some things to keep in mind:

* Please keep the code consistent by adhering to the prevailing naming and
  formatting conventions.  We generally follow the `"Style Guide for Python
  Code" <http://www.python.org/dev/peps/pep-0008/>`_ For docstrings, we follow
  `NumPy's "Docstring Standard"
  <http://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt>`_ and
  `Python's "Docstring Conventions"
  <http://www.python.org/dev/peps/pep-0257/>`_.

* Write tests for all the important functionality you add.  Be sure not to
  break existing tests.

A useful trick for working on the source code is to build in-place so that there
is no need to re-install after each change.  This can be done with the following
command ::

    python setup.py build_ext -i

The ``kwant`` subdirectory of the source distribution will be thus turned into
a proper Python package that can be imported.  To be able to import Kwant from
within Python, one can either work in the root directory of the distribution
(where the subdirectory ``kwant`` is located), or make a (symbolic) link from
somewhere in the Python search path to the the package subdirectory.