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

.. only:: html

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

        Click :ref:`here <sphx_glr_download_tutorials_provisional_mosaic.py>`
        to download the full example code

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

.. _sphx_glr_tutorials_provisional_mosaic.py:


=======================================
Complex and semantic figure composition
=======================================

.. warning::

   This tutorial documents experimental / provisional API.
   We are releasing this in v3.3 to get user feedback.  We may
   make breaking changes in future versions with no warning.


Laying out Axes in a Figure in a non uniform grid can be both tedious
and verbose.  For dense, even grids we have `.Figure.subplots` but for
more complex layouts, such as Axes that span multiple columns / rows
of the layout or leave some areas of the Figure blank, you can use
`.gridspec.GridSpec` (see :doc:`/tutorials/intermediate/gridspec`) or
manually place your axes.  `.Figure.subplot_mosaic` aims to provide an
interface to visually lay out your axes (as either ASCII art or nested
lists) to streamline this process.

This interface naturally supports naming your axes.
`.Figure.subplot_mosaic` returns a dictionary keyed on the
labels used to lay out the Figure.  By returning data structures with
names, it is easier to write plotting code that is independent of the
Figure layout.


This is inspired by a `proposed MEP
<https://github.com/matplotlib/matplotlib/pull/4384>`__ and the
`patchwork <https://github.com/thomasp85/patchwork>`__ library for R.
While we do not implement the operator overloading style, we do
provide a Pythonic API for specifying (nested) Axes layouts.

.. GENERATED FROM PYTHON SOURCE LINES 36-58

.. code-block:: default

    import matplotlib.pyplot as plt
    import numpy as np


    # Helper function used for visualization in the following examples
    def identify_axes(ax_dict, fontsize=48):
        """
        Helper to identify the Axes in the examples below.

        Draws the label in a large font in the center of the Axes.

        Parameters
        ----------
        ax_dict : Dict[str, Axes]
            Mapping between the title / label and the Axes.

        fontsize : int, optional
            How big the label should be
        """
        kw = dict(ha="center", va="center", fontsize=fontsize, color="darkgrey")
        for k, ax in ax_dict.items():
            ax.text(0.5, 0.5, k, transform=ax.transAxes, **kw)







.. GENERATED FROM PYTHON SOURCE LINES 59-61

If we want a 2x2 grid we can use `.Figure.subplots` which returns a 2D array
of `.axes.Axes` which we can index into to do our plotting.

.. GENERATED FROM PYTHON SOURCE LINES 61-77

.. code-block:: default

    np.random.seed(19680801)
    hist_data = np.random.randn(1_500)


    fig = plt.figure(constrained_layout=True)
    ax_array = fig.subplots(2, 2, squeeze=False)

    ax_array[0, 0].bar(['a', 'b', 'c'], [5, 7, 9])
    ax_array[0, 1].plot([1, 2, 3])
    ax_array[1, 0].hist(hist_data, bins='auto')
    ax_array[1, 1].imshow([[1, 2], [2, 1]])

    identify_axes(
        {(j, k): a for j, r in enumerate(ax_array) for k, a in enumerate(r)}
    )




.. image:: /tutorials/provisional/images/sphx_glr_mosaic_001.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 78-80

Using `.Figure.subplot_mosaic` we can produce the same layout but give the
axes semantic names

.. GENERATED FROM PYTHON SOURCE LINES 80-91

.. code-block:: default


    fig = plt.figure(constrained_layout=True)
    ax_dict = fig.subplot_mosaic(
        [['bar',  'plot'],
         ['hist', 'image']])
    ax_dict['bar'].bar(['a', 'b', 'c'], [5, 7, 9])
    ax_dict['plot'].plot([1, 2, 3])
    ax_dict['hist'].hist(hist_data)
    ax_dict['image'].imshow([[1, 2], [2, 1]])
    identify_axes(ax_dict)




.. image:: /tutorials/provisional/images/sphx_glr_mosaic_002.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 92-96

A key difference between `.Figure.subplots` and
`.Figure.subplot_mosaic` is the return value. While the former
returns an array for index access, the latter returns a dictionary
mapping the labels to the `.axes.Axes` instances created

.. GENERATED FROM PYTHON SOURCE LINES 96-100

.. code-block:: default


    print(ax_dict)






.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    {'plot': <AxesSubplot:label='plot'>, 'hist': <AxesSubplot:label='hist'>, 'image': <AxesSubplot:label='image'>, 'bar': <AxesSubplot:label='bar'>}




.. GENERATED FROM PYTHON SOURCE LINES 101-106

String short-hand
=================

By restricting our axes labels to single characters we can use Using we can
"draw" the Axes we want as "ASCII art".  The following

.. GENERATED FROM PYTHON SOURCE LINES 106-113

.. code-block:: default



    layout = """
        AB
        CD
        """








.. GENERATED FROM PYTHON SOURCE LINES 114-117

will give us 4 Axes laid out in a 2x2 grid and generates the same
figure layout as above (but now labeled with ``{"A", "B", "C",
"D"}`` rather than ``{"bar", "plot", "hist", "image"}``).

.. GENERATED FROM PYTHON SOURCE LINES 117-123

.. code-block:: default


    fig = plt.figure(constrained_layout=True)
    ax_dict = fig.subplot_mosaic(layout)
    identify_axes(ax_dict)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_003.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 124-130

Something we can do with `.Figure.subplot_mosaic` that you can not
do with `.Figure.subplots` is specify that an Axes should span
several rows or columns.

If we want to re-arrange our four Axes to have C be a horizontal
span on the bottom and D be a vertical span on the right we would do

.. GENERATED FROM PYTHON SOURCE LINES 130-139

.. code-block:: default


    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        """
        ABD
        CCD
        """
    )
    identify_axes(axd)




.. image:: /tutorials/provisional/images/sphx_glr_mosaic_004.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 140-142

If we do not want to fill in all the spaces in the Figure with Axes,
we can specify some spaces in the grid to be blank

.. GENERATED FROM PYTHON SOURCE LINES 142-154

.. code-block:: default



    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        """
        A.C
        BBB
        .D.
        """
    )
    identify_axes(axd)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_005.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 155-158

If we prefer to use another character (rather than a period ``"."``)
to mark the empty space, we can use *empty_sentinel* to specify the
character to use.

.. GENERATED FROM PYTHON SOURCE LINES 158-169

.. code-block:: default


    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        """
        aX
        Xb
        """,
        empty_sentinel="X",
    )
    identify_axes(axd)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_006.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 170-172

Internally there is no meaning attached to the letters we use, any
Unicode code point is valid!

.. GENERATED FROM PYTHON SOURCE LINES 173-180

.. code-block:: default


    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        """αб
           ℝ☢"""
    )
    identify_axes(axd)




.. image:: /tutorials/provisional/images/sphx_glr_mosaic_007.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 181-194

It is not recommended to use white space as either a label or an
empty sentinel with the string shorthand because it may be stripped
while processing the input.

Controlling layout and subplot creation
=======================================

This feature is built on top of `.gridspec` and you can pass the
keyword arguments through to the underlying `.gridspec.GridSpec`
(the same as `.Figure.subplots`).

In this case we want to use the input to specify the arrangement,
but set the relative widths of the rows / columns via *gridspec_kw*.

.. GENERATED FROM PYTHON SOURCE LINES 194-211

.. code-block:: default



    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        """
        .a.
        bAc
        .d.
        """,
        gridspec_kw={
            # set the height ratios between the rows
            "height_ratios": [1, 3.5, 1],
            # set the width ratios between the columns
            "width_ratios": [1, 3.5, 1],
        },
    )
    identify_axes(axd)




.. image:: /tutorials/provisional/images/sphx_glr_mosaic_008.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 212-215

Or use the {*left*, *right*, *bottom*, *top*} keyword arguments to
position the overall layout to put multiple versions of the same
layout in a figure

.. GENERATED FROM PYTHON SOURCE LINES 215-246

.. code-block:: default


    layout = """AA
                BC"""
    fig = plt.figure()
    axd = fig.subplot_mosaic(
        layout,
        gridspec_kw={
            "bottom": 0.25,
            "top": 0.95,
            "left": 0.1,
            "right": 0.5,
            "wspace": 0.5,
            "hspace": 0.5,
        },
    )
    identify_axes(axd)

    axd = fig.subplot_mosaic(
        layout,
        gridspec_kw={
            "bottom": 0.05,
            "top": 0.75,
            "left": 0.6,
            "right": 0.95,
            "wspace": 0.5,
            "hspace": 0.5,
        },
    )
    identify_axes(axd)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_009.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 247-249

We can also pass through arguments used to create the subplots
(again, the same as `.Figure.subplots`).

.. GENERATED FROM PYTHON SOURCE LINES 249-257

.. code-block:: default



    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        "AB", subplot_kw={"projection": "polar"}
    )
    identify_axes(axd)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_010.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 258-264

Nested List input
=================

Everything we can do with the string short-hand we can also do when
passing in a list (internally we convert the string shorthand to a nested
list), for example using spans, blanks, and *gridspec_kw*:

.. GENERATED FROM PYTHON SOURCE LINES 264-275

.. code-block:: default


    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        [["main", "zoom"],
         ["main", "BLANK"]
         ],
        empty_sentinel="BLANK",
        gridspec_kw={"width_ratios": [2, 1]}
    )
    identify_axes(axd)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_011.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 276-278

In addition, using the list input we can specify nested layouts.  Any element
of the inner list can be another set of nested lists:

.. GENERATED FROM PYTHON SOURCE LINES 278-294

.. code-block:: default


    inner = [
        ["inner A"],
        ["inner B"],
    ]

    outer_nested_layout = [
        ["main", inner],
        ["bottom", "bottom"],
    ]
    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        outer_nested_layout, empty_sentinel=None
    )
    identify_axes(axd, fontsize=36)





.. image:: /tutorials/provisional/images/sphx_glr_mosaic_012.png
    :alt: mosaic
    :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 295-296

We can also pass in a 2D NumPy array to do things like

.. GENERATED FROM PYTHON SOURCE LINES 296-303

.. code-block:: default

    layout = np.zeros((4, 4), dtype=int)
    for j in range(4):
        layout[j, j] = j + 1
    axd = plt.figure(constrained_layout=True).subplot_mosaic(
        layout, empty_sentinel=0
    )
    identify_axes(axd)



.. image:: /tutorials/provisional/images/sphx_glr_mosaic_013.png
    :alt: mosaic
    :class: sphx-glr-single-img






.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  10.505 seconds)


.. _sphx_glr_download_tutorials_provisional_mosaic.py:


.. only :: html

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



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

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



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

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


.. only:: html

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

    Keywords: matplotlib code example, codex, python plot, pyplot
    `Gallery generated by Sphinx-Gallery
    <https://sphinx-gallery.readthedocs.io>`_
