| r""" | |
| .. redirect-from:: /tutorials/text/pgf | |
| .. _pgf: | |
| ************************************************************ | |
| Text rendering with XeLaTeX/LuaLaTeX via the ``pgf`` backend | |
| ************************************************************ | |
| Using the ``pgf`` backend, Matplotlib can export figures as pgf drawing | |
| commands that can be processed with pdflatex, xelatex or lualatex. XeLaTeX and | |
| LuaLaTeX have full Unicode support and can use any font that is installed in | |
| the operating system, making use of advanced typographic features of OpenType, | |
| AAT and Graphite. Pgf pictures created by ``plt.savefig('figure.pgf')`` | |
| can be embedded as raw commands in LaTeX documents. Figures can also be | |
| directly compiled and saved to PDF with ``plt.savefig('figure.pdf')`` by | |
| switching the backend :: | |
| matplotlib.use('pgf') | |
| or by explicitly requesting the use of the ``pgf`` backend :: | |
| plt.savefig('figure.pdf', backend='pgf') | |
| or by registering it for handling pdf output :: | |
| from matplotlib.backends.backend_pgf import FigureCanvasPgf | |
| matplotlib.backend_bases.register_backend('pdf', FigureCanvasPgf) | |
| The last method allows you to keep using regular interactive backends and to | |
| save xelatex, lualatex or pdflatex compiled PDF files from the graphical user | |
| interface. | |
| Matplotlib's pgf support requires a recent LaTeX_ installation that includes | |
| the TikZ/PGF packages (such as TeXLive_), preferably with XeLaTeX or LuaLaTeX | |
| installed. If either pdftocairo or ghostscript is present on your system, | |
| figures can optionally be saved to PNG images as well. The executables | |
| for all applications must be located on your :envvar:`PATH`. | |
| `.rcParams` that control the behavior of the pgf backend: | |
| ================= ===================================================== | |
| Parameter Documentation | |
| ================= ===================================================== | |
| pgf.preamble Lines to be included in the LaTeX preamble | |
| pgf.rcfonts Setup fonts from rc params using the fontspec package | |
| pgf.texsystem Either "xelatex" (default), "lualatex" or "pdflatex" | |
| ================= ===================================================== | |
| .. note:: | |
| TeX defines a set of special characters, such as:: | |
| # $ % & ~ _ ^ \ { } | |
| Generally, these characters must be escaped correctly. For convenience, | |
| some characters (_, ^, %) are automatically escaped outside of math | |
| environments. Other characters are not escaped as they are commonly needed | |
| in actual TeX expressions. However, one can configure TeX to treat them as | |
| "normal" characters (known as "catcode 12" to TeX) via a custom preamble, | |
| such as:: | |
| plt.rcParams["pgf.preamble"] = ( | |
| r"\AtBeginDocument{\catcode`\&=12\catcode`\#=12}") | |
| .. _pgf-rcfonts: | |
| Multi-Page PDF Files | |
| ==================== | |
| The pgf backend also supports multipage pdf files using | |
| `~.backend_pgf.PdfPages` | |
| .. code-block:: python | |
| from matplotlib.backends.backend_pgf import PdfPages | |
| import matplotlib.pyplot as plt | |
| with PdfPages('multipage.pdf', metadata={'author': 'Me'}) as pdf: | |
| fig1, ax1 = plt.subplots() | |
| ax1.plot([1, 5, 3]) | |
| pdf.savefig(fig1) | |
| fig2, ax2 = plt.subplots() | |
| ax2.plot([1, 5, 3]) | |
| pdf.savefig(fig2) | |
| Font specification | |
| ================== | |
| The fonts used for obtaining the size of text elements or when compiling | |
| figures to PDF are usually defined in the `.rcParams`. You can also use the | |
| LaTeX default Computer Modern fonts by clearing the lists for :rc:`font.serif`, | |
| :rc:`font.sans-serif` or :rc:`font.monospace`. Please note that the glyph | |
| coverage of these fonts is very limited. If you want to keep the Computer | |
| Modern font face but require extended Unicode support, consider installing the | |
| `Computer Modern Unicode`__ fonts *CMU Serif*, *CMU Sans Serif*, etc. | |
| __ https://sourceforge.net/projects/cm-unicode/ | |
| When saving to ``.pgf``, the font configuration Matplotlib used for the | |
| layout of the figure is included in the header of the text file. | |
| .. literalinclude:: /gallery/userdemo/pgf_fonts.py | |
| :end-before: fig.savefig | |
| .. _pgf-preamble: | |
| Custom preamble | |
| =============== | |
| Full customization is possible by adding your own commands to the preamble. | |
| Use :rc:`pgf.preamble` if you want to configure the math fonts, | |
| using ``unicode-math`` for example, or for loading additional packages. Also, | |
| if you want to do the font configuration yourself instead of using the fonts | |
| specified in the rc parameters, make sure to disable :rc:`pgf.rcfonts`. | |
| .. only:: html | |
| .. literalinclude:: /gallery/userdemo/pgf_preamble_sgskip.py | |
| :end-before: fig.savefig | |
| .. only:: latex | |
| .. literalinclude:: /gallery/userdemo/pgf_preamble_sgskip.py | |
| :end-before: import matplotlib.pyplot as plt | |
| .. _pgf-texsystem: | |
| Choosing the TeX system | |
| ======================= | |
| The TeX system to be used by Matplotlib is chosen by :rc:`pgf.texsystem`. | |
| Possible values are ``'xelatex'`` (default), ``'lualatex'`` and ``'pdflatex'``. | |
| Please note that when selecting pdflatex, the fonts and Unicode handling must | |
| be configured in the preamble. | |
| .. literalinclude:: /gallery/userdemo/pgf_texsystem.py | |
| :end-before: fig.savefig | |
| .. _pgf-troubleshooting: | |
| Troubleshooting | |
| =============== | |
| * Please note that the TeX packages found in some Linux distributions and | |
| MiKTeX installations are dramatically outdated. Make sure to update your | |
| package catalog and upgrade or install a recent TeX distribution. | |
| * On Windows, the :envvar:`PATH` environment variable may need to be modified | |
| to include the directories containing the latex, dvipng and ghostscript | |
| executables. See :ref:`environment-variables` and | |
| :ref:`setting-windows-environment-variables` for details. | |
| * Sometimes the font rendering in figures that are saved to png images is | |
| very bad. This happens when the pdftocairo tool is not available and | |
| ghostscript is used for the pdf to png conversion. | |
| * Make sure what you are trying to do is possible in a LaTeX document, | |
| that your LaTeX syntax is valid and that you are using raw strings | |
| if necessary to avoid unintended escape sequences. | |
| * :rc:`pgf.preamble` provides lots of flexibility, and lots of | |
| ways to cause problems. When experiencing problems, try to minimalize or | |
| disable the custom preamble. | |
| * Configuring an ``unicode-math`` environment can be a bit tricky. The | |
| TeXLive distribution for example provides a set of math fonts which are | |
| usually not installed system-wide. XeTeX, unlike LuaLatex, cannot find | |
| these fonts by their name, which is why you might have to specify | |
| ``\setmathfont{xits-math.otf}`` instead of ``\setmathfont{XITS Math}`` or | |
| alternatively make the fonts available to your OS. See this | |
| `tex.stackexchange.com question`__ for more details. | |
| __ https://tex.stackexchange.com/q/43642/ | |
| * If the font configuration used by Matplotlib differs from the font setting | |
| in yout LaTeX document, the alignment of text elements in imported figures | |
| may be off. Check the header of your ``.pgf`` file if you are unsure about | |
| the fonts Matplotlib used for the layout. | |
| * Vector images and hence ``.pgf`` files can become bloated if there are a lot | |
| of objects in the graph. This can be the case for image processing or very | |
| big scatter graphs. In an extreme case this can cause TeX to run out of | |
| memory: "TeX capacity exceeded, sorry" You can configure latex to increase | |
| the amount of memory available to generate the ``.pdf`` image as discussed on | |
| `tex.stackexchange.com <https://tex.stackexchange.com/q/7953/>`_. | |
| Another way would be to "rasterize" parts of the graph causing problems | |
| using either the ``rasterized=True`` keyword, or ``.set_rasterized(True)`` as | |
| per :doc:`this example </gallery/misc/rasterization_demo>`. | |
| * Various math fonts are compiled and rendered only if corresponding font | |
| packages are loaded. Specifically, when using ``\mathbf{}`` on Greek letters, | |
| the default computer modern font may not contain them, in which case the | |
| letter is not rendered. In such scenarios, the ``lmodern`` package should be | |
| loaded. | |
| * If you still need help, please see :ref:`reporting-problems` | |
| .. _LaTeX: http://www.tug.org | |
| .. _TeXLive: http://www.tug.org/texlive/ | |
| """ | |