.. only:: html

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

        Click :ref:`here <sphx_glr_download_tutorials_intermediate_gridspec.py>`     to download the full example code
    .. rst-class:: sphx-glr-example-title

    .. _sphx_glr_tutorials_intermediate_gridspec.py:


=============================================================
Customizing Figure Layouts Using GridSpec and Other Functions
=============================================================

How to create grid-shaped combinations of axes.

    :func:`~matplotlib.pyplot.subplots`
        Perhaps the primary function used to create figures and axes.
        It's also similar to :func:`.matplotlib.pyplot.subplot`,
        but creates and places all axes on the figure at once.  See also
        `matplotlib.figure.Figure.subplots`.

    :class:`~matplotlib.gridspec.GridSpec`
        Specifies the geometry of the grid that a subplot will be
        placed. The number of rows and number of columns of the grid
        need to be set. Optionally, the subplot layout parameters
        (e.g., left, right, etc.) can be tuned.

    :class:`~matplotlib.gridspec.SubplotSpec`
        Specifies the location of the subplot in the given *GridSpec*.

    :func:`~matplotlib.pyplot.subplot2grid`
        A helper function that is similar to
        :func:`~matplotlib.pyplot.subplot`,
        but uses 0-based indexing and let subplot to occupy multiple cells.
        This function is not covered in this tutorial.


.. code-block:: default


    import matplotlib
    import matplotlib.pyplot as plt
    import matplotlib.gridspec as gridspec








Basic Quickstart Guide
======================

These first two examples show how to create a basic 2-by-2 grid using
both :func:`~matplotlib.pyplot.subplots` and :mod:`~matplotlib.gridspec`.

Using :func:`~matplotlib.pyplot.subplots` is quite simple.
It returns a :class:`~matplotlib.figure.Figure` instance and an array of
:class:`~matplotlib.axes.Axes` objects.


.. code-block:: default


    fig1, f1_axes = plt.subplots(ncols=2, nrows=2, constrained_layout=True)




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_001.png
    :alt: gridspec
    :class: sphx-glr-single-img





For a simple use case such as this, :mod:`~matplotlib.gridspec` is
perhaps overly verbose.
You have to create the figure and :class:`~matplotlib.gridspec.GridSpec`
instance separately, then pass elements of gridspec instance to the
:func:`~matplotlib.figure.Figure.add_subplot` method to create the axes
objects.
The elements of the gridspec are accessed in generally the same manner as
numpy arrays.


.. code-block:: default


    fig2 = plt.figure(constrained_layout=True)
    spec2 = gridspec.GridSpec(ncols=2, nrows=2, figure=fig2)
    f2_ax1 = fig2.add_subplot(spec2[0, 0])
    f2_ax2 = fig2.add_subplot(spec2[0, 1])
    f2_ax3 = fig2.add_subplot(spec2[1, 0])
    f2_ax4 = fig2.add_subplot(spec2[1, 1])




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_002.png
    :alt: gridspec
    :class: sphx-glr-single-img





The power of gridspec comes in being able to create subplots that span
rows and columns.  Note the `NumPy slice syntax
<https://docs.scipy.org/doc/numpy/reference/arrays.indexing.html>`_
for selecting the part of the gridspec each subplot will occupy.

Note that we have also used the convenience method `.Figure.add_gridspec`
instead of `.gridspec.GridSpec`, potentially saving the user an import,
and keeping the namespace cleaner.


.. code-block:: default


    fig3 = plt.figure(constrained_layout=True)
    gs = fig3.add_gridspec(3, 3)
    f3_ax1 = fig3.add_subplot(gs[0, :])
    f3_ax1.set_title('gs[0, :]')
    f3_ax2 = fig3.add_subplot(gs[1, :-1])
    f3_ax2.set_title('gs[1, :-1]')
    f3_ax3 = fig3.add_subplot(gs[1:, -1])
    f3_ax3.set_title('gs[1:, -1]')
    f3_ax4 = fig3.add_subplot(gs[-1, 0])
    f3_ax4.set_title('gs[-1, 0]')
    f3_ax5 = fig3.add_subplot(gs[-1, -2])
    f3_ax5.set_title('gs[-1, -2]')




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_003.png
    :alt: gs[0, :], gs[1, :-1], gs[1:, -1], gs[-1, 0], gs[-1, -2]
    :class: sphx-glr-single-img


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

 Out:

 .. code-block:: none


    Text(0.5, 1.0, 'gs[-1, -2]')



:mod:`~matplotlib.gridspec` is also indispensable for creating subplots
of different widths via a couple of methods.

The method shown here is similar to the one above and initializes a
uniform grid specification,
and then uses numpy indexing and slices to allocate multiple
"cells" for a given subplot.


.. code-block:: default


    fig4 = plt.figure(constrained_layout=True)
    spec4 = fig4.add_gridspec(ncols=2, nrows=2)
    anno_opts = dict(xy=(0.5, 0.5), xycoords='axes fraction',
                     va='center', ha='center')

    f4_ax1 = fig4.add_subplot(spec4[0, 0])
    f4_ax1.annotate('GridSpec[0, 0]', **anno_opts)
    fig4.add_subplot(spec4[0, 1]).annotate('GridSpec[0, 1:]', **anno_opts)
    fig4.add_subplot(spec4[1, 0]).annotate('GridSpec[1:, 0]', **anno_opts)
    fig4.add_subplot(spec4[1, 1]).annotate('GridSpec[1:, 1:]', **anno_opts)




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_004.png
    :alt: gridspec
    :class: sphx-glr-single-img


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

 Out:

 .. code-block:: none


    Text(0.5, 0.5, 'GridSpec[1:, 1:]')



Another option is to use the ``width_ratios`` and ``height_ratios``
parameters. These keyword arguments are lists of numbers.
Note that absolute values are meaningless, only their relative ratios
matter. That means that ``width_ratios=[2, 4, 8]`` is equivalent to
``width_ratios=[1, 2, 4]`` within equally wide figures.
For the sake of demonstration, we'll blindly create the axes within
``for`` loops since we won't need them later.


.. code-block:: default


    fig5 = plt.figure(constrained_layout=True)
    widths = [2, 3, 1.5]
    heights = [1, 3, 2]
    spec5 = fig5.add_gridspec(ncols=3, nrows=3, width_ratios=widths,
                              height_ratios=heights)
    for row in range(3):
        for col in range(3):
            ax = fig5.add_subplot(spec5[row, col])
            label = 'Width: {}\nHeight: {}'.format(widths[col], heights[row])
            ax.annotate(label, (0.1, 0.5), xycoords='axes fraction', va='center')




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_005.png
    :alt: gridspec
    :class: sphx-glr-single-img





Learning to use ``width_ratios`` and ``height_ratios`` is particularly
useful since the top-level function :func:`~matplotlib.pyplot.subplots`
accepts them within the ``gridspec_kw`` parameter.
For that matter, any parameter accepted by
:class:`~matplotlib.gridspec.GridSpec` can be passed to
:func:`~matplotlib.pyplot.subplots` via the ``gridspec_kw`` parameter.
This example recreates the previous figure without directly using a
gridspec instance.


.. code-block:: default


    gs_kw = dict(width_ratios=widths, height_ratios=heights)
    fig6, f6_axes = plt.subplots(ncols=3, nrows=3, constrained_layout=True,
                                 gridspec_kw=gs_kw)
    for r, row in enumerate(f6_axes):
        for c, ax in enumerate(row):
            label = 'Width: {}\nHeight: {}'.format(widths[c], heights[r])
            ax.annotate(label, (0.1, 0.5), xycoords='axes fraction', va='center')




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_006.png
    :alt: gridspec
    :class: sphx-glr-single-img





The ``subplots`` and ``get_gridspec`` methods can be combined since it is
sometimes more convenient to make most of the subplots using ``subplots``
and then remove some and combine them.  Here we create a layout with
the bottom two axes in the last column combined.


.. code-block:: default


    fig7, f7_axs = plt.subplots(ncols=3, nrows=3)
    gs = f7_axs[1, 2].get_gridspec()
    # remove the underlying axes
    for ax in f7_axs[1:, -1]:
        ax.remove()
    axbig = fig7.add_subplot(gs[1:, -1])
    axbig.annotate('Big Axes \nGridSpec[1:, -1]', (0.1, 0.5),
                   xycoords='axes fraction', va='center')

    fig7.tight_layout()




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_007.png
    :alt: gridspec
    :class: sphx-glr-single-img





Fine Adjustments to a Gridspec Layout
=====================================

When a GridSpec is explicitly used, you can adjust the layout
parameters of subplots that are created from the GridSpec.  Note this
option is not compatible with ``constrained_layout`` or
`.Figure.tight_layout` which both adjust subplot sizes to fill the
figure.


.. code-block:: default


    fig8 = plt.figure(constrained_layout=False)
    gs1 = fig8.add_gridspec(nrows=3, ncols=3, left=0.05, right=0.48, wspace=0.05)
    f8_ax1 = fig8.add_subplot(gs1[:-1, :])
    f8_ax2 = fig8.add_subplot(gs1[-1, :-1])
    f8_ax3 = fig8.add_subplot(gs1[-1, -1])




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_008.png
    :alt: gridspec
    :class: sphx-glr-single-img





This is similar to :func:`~matplotlib.pyplot.subplots_adjust`, but it only
affects the subplots that are created from the given GridSpec.

For example, compare the left and right sides of this figure:


.. code-block:: default


    fig9 = plt.figure(constrained_layout=False)
    gs1 = fig9.add_gridspec(nrows=3, ncols=3, left=0.05, right=0.48,
                            wspace=0.05)
    f9_ax1 = fig9.add_subplot(gs1[:-1, :])
    f9_ax2 = fig9.add_subplot(gs1[-1, :-1])
    f9_ax3 = fig9.add_subplot(gs1[-1, -1])

    gs2 = fig9.add_gridspec(nrows=3, ncols=3, left=0.55, right=0.98,
                            hspace=0.05)
    f9_ax4 = fig9.add_subplot(gs2[:, :-1])
    f9_ax5 = fig9.add_subplot(gs2[:-1, -1])
    f9_ax6 = fig9.add_subplot(gs2[-1, -1])




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_009.png
    :alt: gridspec
    :class: sphx-glr-single-img





GridSpec using SubplotSpec
==========================

You can create GridSpec from the :class:`~matplotlib.gridspec.SubplotSpec`,
in which case its layout parameters are set to that of the location of
the given SubplotSpec.

Note this is also available from the more verbose
`.gridspec.GridSpecFromSubplotSpec`.


.. code-block:: default


    fig10 = plt.figure(constrained_layout=True)
    gs0 = fig10.add_gridspec(1, 2)

    gs00 = gs0[0].subgridspec(2, 3)
    gs01 = gs0[1].subgridspec(3, 2)

    for a in range(2):
        for b in range(3):
            fig10.add_subplot(gs00[a, b])
            fig10.add_subplot(gs01[b, a])




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_010.png
    :alt: gridspec
    :class: sphx-glr-single-img





A Complex Nested GridSpec using SubplotSpec
===========================================

Here's a more sophisticated example of nested GridSpec where we put
a box around each cell of the outer 4x4 grid, by hiding appropriate
spines in each of the inner 3x3 grids.


.. code-block:: default


    import numpy as np


    def squiggle_xy(a, b, c, d, i=np.arange(0.0, 2*np.pi, 0.05)):
        return np.sin(i*a)*np.cos(i*b), np.sin(i*c)*np.cos(i*d)


    fig11 = plt.figure(figsize=(8, 8), constrained_layout=False)
    outer_grid = fig11.add_gridspec(4, 4, wspace=0, hspace=0)

    for a in range(4):
        for b in range(4):
            # gridspec inside gridspec
            inner_grid = outer_grid[a, b].subgridspec(3, 3, wspace=0, hspace=0)
            axs = inner_grid.subplots()  # Create all subplots for the inner grid.
            for (c, d), ax in np.ndenumerate(axs):
                ax.plot(*squiggle_xy(a + 1, b + 1, c + 1, d + 1))
                ax.set(xticks=[], yticks=[])

    # show only the outside spines
    for ax in fig11.get_axes():
        ax.spines['top'].set_visible(ax.is_first_row())
        ax.spines['bottom'].set_visible(ax.is_last_row())
        ax.spines['left'].set_visible(ax.is_first_col())
        ax.spines['right'].set_visible(ax.is_last_col())

    plt.show()




.. image:: /tutorials/intermediate/images/sphx_glr_gridspec_011.png
    :alt: gridspec
    :class: sphx-glr-single-img





------------

References
""""""""""

The usage of the following functions and methods is shown in this example:


.. code-block:: default


    matplotlib.pyplot.subplots
    matplotlib.figure.Figure.add_gridspec
    matplotlib.figure.Figure.add_subplot
    matplotlib.gridspec.GridSpec
    matplotlib.gridspec.SubplotSpec.subgridspec
    matplotlib.gridspec.GridSpecFromSubplotSpec








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

   **Total running time of the script:** ( 0 minutes  12.046 seconds)


.. _sphx_glr_download_tutorials_intermediate_gridspec.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: gridspec.py <gridspec.py>`



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

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


.. only:: html

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

    Keywords: matplotlib code example, codex, python plot, pyplot
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