.. _documenting-matplotlib: ********************** Documenting matplotlib ********************** Getting started =============== The documentation for matplotlib is generated from ReStructured Text using the Sphinx_ documentation generation tool. Sphinx-1.0 or later and numpydoc 0.4 or later is required. The documentation sources are found in the :file:`doc/` directory in the trunk. To build the users guide in html format, cd into :file:`doc/` and do:: python make.py html or:: ./make.py html you can also pass a ``latex`` flag to make.py to build a pdf, or pass no arguments to build everything. The output produced by Sphinx can be configured by editing the :file:`conf.py` file located in the :file:`doc/`. Organization of matplotlib's documentation ========================================== The actual ReStructured Text files are kept in :file:`doc/users`, :file:`doc/devel`, :file:`doc/api` and :file:`doc/faq`. The main entry point is :file:`doc/index.rst`, which pulls in the :file:`index.rst` file for the users guide, developers guide, api reference, and faqs. The documentation suite is built as a single document in order to make the most effective use of cross referencing, we want to make navigating the Matplotlib documentation as easy as possible. Additional files can be added to the various guides by including their base file name (the .rst extension is not necessary) in the table of contents. It is also possible to include other documents through the use of an include statement, such as:: .. include:: ../../TODO docstrings ---------- In addition to the "narrative" documentation described above, matplotlib also defines its API reference documentation in docstrings. For the most part, these are standard Python docstrings, but matplotlib also includes some features to better support documenting getters and setters. Matplotlib uses artist introspection of docstrings to support properties. All properties that you want to support through ``setp`` and ``getp`` should have a ``set_property`` and ``get_property`` method in the :class:`~matplotlib.artist.Artist` class. Yes, this is not ideal given python properties or enthought traits, but it is a historical legacy for now. The setter methods use the docstring with the ACCEPTS token to indicate the type of argument the method accepts. e.g., in :class:`matplotlib.lines.Line2D`:: # in lines.py def set_linestyle(self, linestyle): """ Set the linestyle of the line ACCEPTS: [ '-' | '--' | '-.' | ':' | 'steps' | 'None' | ' ' | '' ] """ Since matplotlib uses a lot of pass-through ``kwargs``, e.g., in every function that creates a line (:func:`~matplotlib.pyplot.plot`, :func:`~matplotlib.pyplot.semilogx`, :func:`~matplotlib.pyplot.semilogy`, etc...), it can be difficult for the new user to know which ``kwargs`` are supported. Matplotlib uses a docstring interpolation scheme to support documentation of every function that takes a ``**kwargs``. The requirements are: 1. single point of configuration so changes to the properties don't require multiple docstring edits. 2. as automated as possible so that as properties change, the docs are updated automagically. The functions :attr:`matplotlib.artist.kwdocd` and :func:`matplotlib.artist.kwdoc` to facilitate this. They combine python string interpolation in the docstring with the matplotlib artist introspection facility that underlies ``setp`` and ``getp``. The ``kwdocd`` is a single dictionary that maps class name to a docstring of ``kwargs``. Here is an example from :mod:`matplotlib.lines`:: # in lines.py artist.kwdocd['Line2D'] = artist.kwdoc(Line2D) Then in any function accepting :class:`~matplotlib.lines.Line2D` pass-through ``kwargs``, e.g., :meth:`matplotlib.axes.Axes.plot`:: # in axes.py def plot(self, *args, **kwargs): """ Some stuff omitted The kwargs are Line2D properties: %(Line2D)s kwargs scalex and scaley, if defined, are passed on to autoscale_view to determine whether the x and y axes are autoscaled; default True. See Axes.autoscale_view for more information """ pass plot.__doc__ = cbook.dedent(plot.__doc__) % artist.kwdocd Note there is a problem for :class:`~matplotlib.artist.Artist` ``__init__`` methods, e.g., :meth:`matplotlib.patches.Patch.__init__`, which supports ``Patch`` ``kwargs``, since the artist inspector cannot work until the class is fully defined and we can't modify the ``Patch.__init__.__doc__`` docstring outside the class definition. There are some some manual hacks in this case, violating the "single entry point" requirement above -- see the ``artist.kwdocd['Patch']`` setting in :mod:`matplotlib.patches`. .. _formatting-mpl-docs: Formatting ========== The Sphinx website contains plenty of documentation_ concerning ReST markup and working with Sphinx in general. Here are a few additional things to keep in mind: * Please familiarize yourself with the Sphinx directives for `inline markup`_. Matplotlib's documentation makes heavy use of cross-referencing and other semantic markup. For example, when referring to external files, use the ``:file:`` directive. * Function arguments and keywords should be referred to using the *emphasis* role. This will keep matplotlib's documentation consistent with Python's documentation:: Here is a description of *argument* Please do not use the `default role`:: Please do not describe `argument` like this. nor the ``literal`` role:: Please do not describe ``argument`` like this. * Sphinx does not support tables with column- or row-spanning cells for latex output. Such tables can not be used when documenting matplotlib. * Mathematical expressions can be rendered as png images in html, and in the usual way by latex. For example: ``:math:`\sin(x_n^2)``` yields: :math:`\sin(x_n^2)`, and:: .. math:: \int_{-\infty}^{\infty}\frac{e^{i\phi}}{1+x^2\frac{e^{i\phi}}{1+x^2}} yields: .. math:: \int_{-\infty}^{\infty}\frac{e^{i\phi}}{1+x^2\frac{e^{i\phi}}{1+x^2}} * Interactive IPython sessions can be illustrated in the documentation using the following directive:: .. sourcecode:: ipython In [69]: lines = plot([1,2,3]) which would yield: .. sourcecode:: ipython In [69]: lines = plot([1,2,3]) * Footnotes [#]_ can be added using ``[#]_``, followed later by:: .. rubric:: Footnotes .. [#] .. rubric:: Footnotes .. [#] For example. * Use the *note* and *warning* directives, sparingly, to draw attention to important comments:: .. note:: Here is a note yields: .. note:: here is a note also: .. warning:: here is a warning * Use the *deprecated* directive when appropriate:: .. deprecated:: 0.98 This feature is obsolete, use something else. yields: .. deprecated:: 0.98 This feature is obsolete, use something else. * Use the *versionadded* and *versionchanged* directives, which have similar syntax to the *deprecated* role:: .. versionadded:: 0.98 The transforms have been completely revamped. .. versionadded:: 0.98 The transforms have been completely revamped. * Use the *seealso* directive, for example:: .. seealso:: Using ReST :ref:`emacs-helpers`: One example A bit about :ref:`referring-to-mpl-docs`: One more yields: .. seealso:: Using ResT :ref:`emacs-helpers`: One example A bit about :ref:`referring-to-mpl-docs`: One more * Please keep the :ref:`glossary` in mind when writing documentation. You can create a references to a term in the glossary with the ``:term:`` role. * The autodoc extension will handle index entries for the API, but additional entries in the index_ need to be explicitly added. .. _Sphinx: http://sphinx.pocoo.org .. _documentation: http://sphinx.pocoo.org/contents.html .. _`inline markup`: http://sphinx.pocoo.org/markup/inline.html .. _index: http://sphinx.pocoo.org/markup/para.html#index-generating-markup * Please limit the text width of docstrings to 70 characters. * Keyword arguments should be described using a definition list. .. note:: matplotlib makes extensive use of keyword arguments as pass-through arguments, there are a many cases where a table is used in place of a definition list for autogenerated sections of docstrings. Figures ======= Dynamically generated figures ----------------------------- Figures can be automatically generated from scripts and included in the docs. It is not necessary to explicitly save the figure in the script, this will be done automatically at build time to ensure that the code that is included runs and produces the advertised figure. The path should be relative to the ``doc`` directory. Any plots specific to the documentation should be added to the ``doc/pyplots`` directory and committed to git. Plots from the ``examples`` directory may be referenced through the symlink ``mpl_examples`` in the ``doc`` directory. e.g.:: .. plot:: mpl_examples/pylab_examples/simple_plot.py The ``:scale:`` directive rescales the image to some percentage of the original size, though we don't recommend using this in most cases since it is probably better to choose the correct figure size and dpi in mpl and let it handle the scaling. Plot directive documentation '''''''''''''''''''''''''''' .. automodule:: matplotlib.sphinxext.plot_directive Static figures -------------- Any figures that rely on optional system configurations need to be handled a little differently. These figures are not to be generated during the documentation build, in order to keep the prerequisites to the documentation effort as low as possible. Please run the :file:`doc/pyplots/make.py` script when adding such figures, and commit the script **and** the images to git. Please also add a line to the README in doc/pyplots for any additional requirements necessary to generate a new figure. Once these steps have been taken, these figures can be included in the usual way:: .. plot:: pyplots/tex_unicode_demo.py :include-source: Examples -------- The source of the files in the ``examples`` directory are automatically included in the HTML docs. An image is generated and included for all examples in the ``api`` and ``pylab_examples`` directories. To exclude the example from having an image rendered, insert the following special comment anywhere in the script:: # -*- noplot -*- Animations ---------- We have a matplotlib google/gmail account with username ``mplgithub`` which we used to setup the github account but can be used for other purposes, like hosting google docs or youtube videos. You can embed a matplotlib animation in the docs by first saving the animation as a movie using :meth:`matplotlib.animation.Animation.save`, and then uploading to `matplotlib's youtube channel `_ and inserting the embedding string youtube provides like:: .. raw:: html An example save command to generate a movie looks like this .. sourcecode:: python ani = animation.FuncAnimation(fig, animate, np.arange(1, len(y)), interval=25, blit=True, init_func=init) ani.save('double_pendulum.mp4', fps=15) Contact Michael Droettboom for the login password to upload youtube videos of google docs to the mplgithub account. .. _referring-to-mpl-docs: Referring to mpl documents ========================== In the documentation, you may want to include to a document in the matplotlib src, e.g., a license file or an image file from `mpl-data`, refer to it via a relative path from the document where the rst file resides, eg, in :file:`users/navigation_toolbar.rst`, we refer to the image icons with:: .. image:: ../../lib/matplotlib/mpl-data/images/subplots.png In the `users` subdirectory, if I want to refer to a file in the mpl-data directory, I use the symlink directory. For example, from `customizing.rst`:: .. literalinclude:: ../../lib/matplotlib/mpl-data/matplotlibrc One exception to this is when referring to the examples dir. Relative paths are extremely confusing in the sphinx plot extensions, so without getting into the dirty details, it is easier to simply include a symlink to the files at the top doc level directory. This way, API documents like :meth:`matplotlib.pyplot.plot` can refer to the examples in a known location. In the top level doc directory we have symlinks pointing to the mpl `examples`:: home:~/mpl/doc> ls -l mpl_* mpl_examples -> ../examples So we can include plots from the examples dir using the symlink:: .. plot:: mpl_examples/pylab_examples/simple_plot.py We used to use a symlink for :file:`mpl-data` too, but the distro becomes very large on platforms that do not support links (eg the font files are duplicated and large) .. _internal-section-refs: Internal section references =========================== To maximize internal consistency in section labeling and references, use hyphen separated, descriptive labels for section references, eg:: .. _howto-webapp: and refer to it using the standard reference syntax:: See :ref:`howto-webapp` Keep in mind that we may want to reorganize the contents later, so let's avoid top level names in references like ``user`` or ``devel`` or ``faq`` unless necessary, because for example the FAQ "what is a backend?" could later become part of the users guide, so the label:: .. _what-is-a-backend is better than:: .. _faq-backend In addition, since underscores are widely used by Sphinx itself, let's prefer hyphens to separate words. Section names, etc ================== For everything but top level chapters, please use ``Upper lower`` for section titles, eg ``Possible hangups`` rather than ``Possible Hangups`` Inheritance diagrams ==================== Class inheritance diagrams can be generated with the ``inheritance-diagram`` directive. To use it, you provide the directive with a number of class or module names (separated by whitespace). If a module name is provided, all classes in that module will be used. All of the ancestors of these classes will be included in the inheritance diagram. A single option is available: *parts* controls how many of parts in the path to the class are shown. For example, if *parts* == 1, the class ``matplotlib.patches.Patch`` is shown as ``Patch``. If *parts* == 2, it is shown as ``patches.Patch``. If *parts* == 0, the full path is shown. Example:: .. inheritance-diagram:: matplotlib.patches matplotlib.lines matplotlib.text :parts: 2 .. inheritance-diagram:: matplotlib.patches matplotlib.lines matplotlib.text :parts: 2 .. _emacs-helpers: Emacs helpers ============= There is an emacs mode `rst.el `_ which automates many important ReST tasks like building and updating table-of-contents, and promoting or demoting section headings. Here is the basic ``.emacs`` configuration:: (require 'rst) (setq auto-mode-alist (append '(("\\.txt$" . rst-mode) ("\\.rst$" . rst-mode) ("\\.rest$" . rst-mode)) auto-mode-alist)) Some helpful functions:: C-c TAB - rst-toc-insert Insert table of contents at point C-c C-u - rst-toc-update Update the table of contents at point C-c C-l rst-shift-region-left Shift region to the left C-c C-r rst-shift-region-right Shift region to the right .. TODO: Add section about uploading docs