
.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "users/explain/text/mathtext.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. meta::
        :keywords: codex

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_users_explain_text_mathtext.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_users_explain_text_mathtext.py:


.. redirect-from:: /tutorials/text/mathtext

.. _mathtext:

Writing mathematical expressions
================================

Matplotlib implements a lightweight TeX expression parser and layout engine and
*Mathtext* is the subset of Tex markup that this engine supports. Note that
Matplotlib can also render all text directly using TeX if :rc:`text.usetex` is
*True*; see :ref:`usetex` for more details.   Mathtext support is available
if :rc:`text.usetex` is *False*.

Any string can be processed as Mathtext by placing the string inside a pair of
dollar signs ``'$'``. Mathtext often contains many backslashes ``'\'``; so that
the backslashes do not need to be escaped, Mathtext is often written using raw
strings. For example:

.. GENERATED FROM PYTHON SOURCE LINES 21-29

.. code-block:: Python


    import matplotlib.pyplot as plt

    fig = plt.figure(figsize=(3, 3), linewidth=1, edgecolor='black')
    fig.text(.2, .7, "plain text: alpha > beta")
    fig.text(.2, .5, "Mathtext: $\\alpha > \\beta$")
    fig.text(.2, .3, r"raw string Mathtext: $\alpha > \beta$")




.. image-sg:: /users/explain/text/images/sphx_glr_mathtext_001.png
   :alt: mathtext
   :srcset: /users/explain/text/images/sphx_glr_mathtext_001.png, /users/explain/text/images/sphx_glr_mathtext_001_2_00x.png 2.00x
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 30-53

.. seealso::

  :doc:`Mathtext example </gallery/text_labels_and_annotations/mathtext_demo>`

TeX does *not* need to be installed to use Mathtext because Matplotlib ships
with the Mathtext parser and engine. The Mathtext layout engine is a fairly
direct adaptation of the layout algorithms in Donald Knuth's TeX. To render
mathematical text using a different TeX engine, see :ref:`usetex`.

.. note::
  To generate html output in documentation that will exactly match the output
  generated by ``mathtext``, use the `matplotlib.sphinxext.mathmpl` Sphinx
  extension.


Special characters
------------------

Mathtext must be placed between a pair of (US) dollar signs ``'$'``. A literal
dollar symbol ``'$'`` in a string containing Mathtext must be escaped using a
backslash: ``'\$'``. A string may contain multiple pairs of dollar signs,
resulting in multiple Mathtext expressions. Strings with an odd number of
dollar signs are rendered solely as plain text.

.. GENERATED FROM PYTHON SOURCE LINES 53-61

.. code-block:: Python


    fig = plt.figure(figsize=(3, 3), linewidth=1, edgecolor='black')
    fig.suptitle("Number of unescaped $")
    fig.text(.1, .7, r"odd: $ \alpha $ = $1")
    fig.text(.1, .5, r"even: $ \beta $= $ 2 $")
    fig.text(.1, .3, r'odd: $ \gamma $= \$3 $')
    fig.text(.1, .1, r'even: $ \delta $ = $ \$4 $')




.. image-sg:: /users/explain/text/images/sphx_glr_mathtext_002.png
   :alt: Number of unescaped $
   :srcset: /users/explain/text/images/sphx_glr_mathtext_002.png, /users/explain/text/images/sphx_glr_mathtext_002_2_00x.png 2.00x
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 62-374

While Mathtext aims for compatibility with regular TeX, it diverges on when
special characters need to be escaped. In TeX the dollar sign must be escaped
``'\$'`` in non-math text, while in Matplotlib the dollar sign must be
escaped when writing Mathtext.

These other special characters are also escaped in non-math TeX, while in
Matplotlib their behavior is dependent on how :rc:`text.usetex` is set::

   # $ % & ~ _ ^ \ { } \( \) \[ \]

See the :ref:`usetex tutorial <usetex>` for more information.


Subscripts and superscripts
---------------------------
To make subscripts and superscripts, use the ``'_'`` and ``'^'`` symbols::

    r'$\alpha_i > \beta_i$'

.. math::

    \alpha_i > \beta_i

To display multi-letter subscripts or superscripts correctly,
you should put them in curly braces ``{...}``::

    r'$\alpha^{ic} > \beta_{ic}$'

.. math::

    \alpha^{ic} > \beta_{ic}

Some symbols automatically put their sub/superscripts under and over the
operator.  For example, to write the sum of :mathmpl:`x_i` from :mathmpl:`0` to
:mathmpl:`\infty`, you could do::

    r'$\sum_{i=0}^\infty x_i$'

.. math::

    \sum_{i=0}^\infty x_i

Fractions, binomials, and stacked numbers
-----------------------------------------
Fractions, binomials, and stacked numbers can be created with the
``\frac{}{}``, ``\binom{}{}`` and ``\genfrac{}{}{}{}{}{}`` commands,
respectively::

    r'$\frac{3}{4} \binom{3}{4} \genfrac{}{}{0}{}{3}{4}$'

produces

.. math::

    \frac{3}{4} \binom{3}{4} \genfrac{}{}{0pt}{}{3}{4}

Fractions can be arbitrarily nested::

    r'$\frac{5 - \frac{1}{x}}{4}$'

produces

.. math::

    \frac{5 - \frac{1}{x}}{4}

Note that special care needs to be taken to place parentheses and brackets
around fractions.  Doing things the obvious way produces brackets that are too
small::

    r'$(\frac{5 - \frac{1}{x}}{4})$'

.. math::

    (\frac{5 - \frac{1}{x}}{4})

The solution is to precede the bracket with ``\left`` and ``\right`` to inform
the parser that those brackets encompass the entire object.::

    r'$\left(\frac{5 - \frac{1}{x}}{4}\right)$'

.. math::

    \left(\frac{5 - \frac{1}{x}}{4}\right)

Radicals
--------
Radicals can be produced with the ``\sqrt[]{}`` command.  For example::

    r'$\sqrt{2}$'

.. math::

    \sqrt{2}

Any base can (optionally) be provided inside square brackets.  Note that the
base must be a simple expression, and cannot contain layout commands such as
fractions or sub/superscripts::

    r'$\sqrt[3]{x}$'

.. math::

    \sqrt[3]{x}

.. _mathtext-fonts:

Fonts
-----

The default font is *italics* for mathematical symbols.

This default can be changed using :rc:`mathtext.default`. For setting rcParams,
see :ref:`customizing`. For example, setting the default to ``regular`` allows
you to use the same font for math text and regular non-math text.

To change fonts, e.g., to write "sin" in a Roman font, enclose the text in a
font command::

    r'$s(t) = \mathcal{A}\mathrm{sin}(2 \omega t)$'

.. math::

    s(t) = \mathcal{A}\mathrm{sin}(2 \omega t)

More conveniently, many commonly used function names that are typeset in
a Roman font have shortcuts.  So the expression above could be written as
follows::

    r'$s(t) = \mathcal{A}\sin(2 \omega t)$'

.. math::

    s(t) = \mathcal{A}\sin(2 \omega t)

Here "s" and "t" are variable in italics font (default), "sin" is in Roman
font, and the amplitude "A" is in calligraphy font.  Note in the example above
the calligraphy ``A`` is squished into the ``sin``.  You can use a spacing
command to add a little whitespace between them::

    r's(t) = \mathcal{A}\/\sin(2 \omega t)'

.. Here we cheat a bit: for HTML math rendering, Sphinx relies on MathJax which
   doesn't actually support the italic correction (\/); instead, use a thin
   space (\,) which is supported.

.. math::

    s(t) = \mathcal{A}\,\sin(2 \omega t)

Mathtext can use DejaVu Sans (default), DejaVu Serif, Computer Modern fonts
from (La)TeX, `STIX <http://www.stixfonts.org/>`_ fonts which are designed
to blend well with Times, or a Unicode font that you provide. The Mathtext
font can be selected via :rc:`mathtext.fontset`.

The choices available with all fonts are:

========================= ================================
Command                   Result
========================= ================================
``\mathrm{Roman}``        :mathmpl:`\mathrm{Roman}`
``\mathit{Italic}``       :mathmpl:`\mathit{Italic}`
``\mathtt{Typewriter}``   :mathmpl:`\mathtt{Typewriter}`
``\mathcal{CALLIGRAPHY}`` :mathmpl:`\mathcal{CALLIGRAPHY}`
========================= ================================

.. rstcheck: ignore-directives=role
.. role:: math-stix(mathmpl)
   :fontset: stix

When using the `STIX <http://www.stixfonts.org/>`_ fonts, you also have the
choice of:

================================ =========================================
Command                          Result
================================ =========================================
``\mathbb{blackboard}``          :math-stix:`\mathbb{blackboard}`
``\mathrm{\mathbb{blackboard}}`` :math-stix:`\mathrm{\mathbb{blackboard}}`
``\mathfrak{Fraktur}``           :math-stix:`\mathfrak{Fraktur}`
``\mathsf{sansserif}``           :math-stix:`\mathsf{sansserif}`
``\mathrm{\mathsf{sansserif}}``  :math-stix:`\mathrm{\mathsf{sansserif}}`
``\mathbfit{bolditalic}``        :math-stix:`\mathbfit{bolditalic}`
================================ =========================================

There are also five global "font sets" to choose from, which are
selected using the ``mathtext.fontset`` parameter in :ref:`matplotlibrc
<matplotlibrc-sample>`.

``dejavusans``: DejaVu Sans
    .. mathmpl::
       :fontset: dejavusans

       \mathcal{R} \prod_{i=\alpha}^{\infty} a_i \sin\left(2\pi fx_i\right)

``dejavuserif``: DejaVu Serif
    .. mathmpl::
       :fontset: dejavuserif

       \mathcal{R} \prod_{i=\alpha}^{\infty} a_i \sin\left(2\pi fx_i\right)

``cm``: Computer Modern (TeX)
    .. mathmpl::
       :fontset: cm

       \mathcal{R} \prod_{i=\alpha}^{\infty} a_i \sin\left(2\pi fx_i\right)

``stix``: STIX (designed to blend well with Times)
    .. mathmpl::
       :fontset: stix

       \mathcal{R} \prod_{i=\alpha}^{\infty} a_i \sin\left(2\pi fx_i\right)

``stixsans``: STIX sans-serif
    .. mathmpl::
       :fontset: stixsans

       \mathcal{R} \prod_{i=\alpha}^{\infty} a_i \sin\left(2\pi fx_i\right)

Additionally, you can use ``\mathdefault{...}`` or its alias
``\mathregular{...}`` to use the font used for regular text outside of
Mathtext.  There are a number of limitations to this approach, most notably
that far fewer symbols will be available, but it can be useful to make math
expressions blend well with other text in the plot.

For compatibility with popular packages, ``\text{...}`` is available and uses the
``\mathrm{...}`` font, but otherwise retains spaces and renders - as a dash
(not minus).

Custom fonts
^^^^^^^^^^^^
Mathtext also provides a way to use custom fonts for math.  This method is
fairly tricky to use, and should be considered an experimental feature for
patient users only.  By setting :rc:`mathtext.fontset` to ``custom``,
you can then set the following parameters, which control which font file to use
for a particular set of math characters.

============================== =================================
Parameter                      Corresponds to
============================== =================================
``mathtext.it``                ``\mathit{}`` or default italic
``mathtext.rm``                ``\mathrm{}`` Roman (upright)
``mathtext.tt``                ``\mathtt{}`` Typewriter (monospace)
``mathtext.bf``                ``\mathbf{}`` bold
``mathtext.bfit``              ``\mathbfit{}`` bold italic
``mathtext.cal``               ``\mathcal{}`` calligraphic
``mathtext.sf``                ``\mathsf{}`` sans-serif
============================== =================================

Each parameter should be set to a fontconfig font descriptor, as defined in
:ref:`fonts`. The fonts used should have a Unicode mapping in order to find
any non-Latin characters, such as Greek.  If you want to use a math symbol
that is not contained in your custom fonts, you can set
:rc:`mathtext.fallback` to either ``'cm'``, ``'stix'`` or ``'stixsans'``
which will cause the Mathtext system to use
characters from an alternative font whenever a particular
character cannot be found in the custom font.

Note that the math glyphs specified in Unicode have evolved over time, and
many fonts may not have glyphs in the correct place for Mathtext.

Accents
-------
An accent command may precede any symbol to add an accent above it.  There are
long and short forms for some of them.

============================== =================================
Command                        Result
============================== =================================
``\acute a`` or ``\'a``        :mathmpl:`\acute a`
``\bar a``                     :mathmpl:`\bar a`
``\breve a``                   :mathmpl:`\breve a`
``\dot a`` or ``\.a``          :mathmpl:`\dot a`
``\ddot a`` or ``\''a``        :mathmpl:`\ddot a`
``\dddot a``                   :mathmpl:`\dddot a`
``\ddddot a``                  :mathmpl:`\ddddot a`
``\grave a`` or ``\`a``        :mathmpl:`\grave a`
``\hat a`` or ``\^a``          :mathmpl:`\hat a`
``\tilde a`` or ``\~a``        :mathmpl:`\tilde a`
``\vec a``                     :mathmpl:`\vec a`
``\overline{abc}``             :mathmpl:`\overline{abc}`
============================== =================================

In addition, there are two special accents that automatically adjust to the
width of the symbols below:

============================== =================================
Command                        Result
============================== =================================
``\widehat{xyz}``              :mathmpl:`\widehat{xyz}`
``\widetilde{xyz}``            :mathmpl:`\widetilde{xyz}`
============================== =================================

Care should be taken when putting accents on lower-case i's and j's.  Note
that in the following ``\imath`` is used to avoid the extra dot over the i::

    r"$\hat i\ \ \hat \imath$"

.. math::

    \hat i\ \ \hat \imath

Symbols
-------
You can also use a large number of the TeX symbols, as in ``\infty``,
``\leftarrow``, ``\sum``, ``\int``.

.. math_symbol_table::

If a particular symbol does not have a name (as is true of many of the more
obscure symbols in the STIX fonts), Unicode characters can also be used::

   r'$\u23ce$'


.. _sphx_glr_download_users_explain_text_mathtext.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: mathtext.ipynb <mathtext.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: mathtext.py <mathtext.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: mathtext.zip <mathtext.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_
