33Scatter plot with histograms
44============================
55
6- Show the marginal distributions of a scatter plot as histograms at the sides of
7- the plot.
6+ Add histograms to the x-axes and y-axes margins of a scatter plot.
7+
8+ This layout features a central scatter plot illustrating the relationship
9+ between x and y, a histogram at the top displaying the distribution of x, and a
10+ histogram on the right showing the distribution of y.
811
912For a nice alignment of the main Axes with the marginals, two options are shown
1013below:
1518While `.Axes.inset_axes` may be a bit more complex, it allows correct handling
1619of main Axes with a fixed aspect ratio.
1720
18- An alternative method to produce a similar figure using the ``axes_grid1``
19- toolkit is shown in the :doc:`/gallery/axes_grid1/scatter_hist_locatable_axes`
20- example. Finally, it is also possible to position all Axes in absolute
21- coordinates using `.Figure.add_axes` (not shown here).
22-
23- Let us first define a function that takes x and y data as input, as well
24- as three Axes, the main Axes for the scatter, and two marginal Axes. It will
25- then create the scatter and histograms inside the provided Axes.
21+ Let us first define a function that takes x and y data as input, as well as
22+ three Axes, the main Axes for the scatter, and two marginal Axes. It will then
23+ create the scatter and histograms inside the provided Axes.
2624"""
2725
2826import matplotlib .pyplot as plt
@@ -55,27 +53,22 @@ def scatter_hist(x, y, ax, ax_histx, ax_histy):
5553
5654
5755# %%
56+ # Defining the Axes positions using subplot_mosaic
57+ # ------------------------------------------------
5858#
59- # Defining the Axes positions using a gridspec
60- # --------------------------------------------
61- #
62- # We define a gridspec with unequal width- and height-ratios to achieve desired
63- # layout. Also see the :ref:`arranging_axes` tutorial.
64-
65- # Start with a square Figure.
66- fig = plt .figure (figsize = (6 , 6 ))
67- # Add a gridspec with two rows and two columns and a ratio of 1 to 4 between
68- # the size of the marginal Axes and the main Axes in both directions.
69- # Also adjust the subplot parameters for a square plot.
70- gs = fig .add_gridspec (2 , 2 , width_ratios = (4 , 1 ), height_ratios = (1 , 4 ),
71- left = 0.1 , right = 0.9 , bottom = 0.1 , top = 0.9 ,
72- wspace = 0.05 , hspace = 0.05 )
73- # Create the Axes.
74- ax = fig .add_subplot (gs [1 , 0 ])
75- ax_histx = fig .add_subplot (gs [0 , 0 ], sharex = ax )
76- ax_histy = fig .add_subplot (gs [1 , 1 ], sharey = ax )
77- # Draw the scatter plot and marginals.
78- scatter_hist (x , y , ax , ax_histx , ax_histy )
59+ # We use the `~.pyplot.subplot_mosaic` function to define the positions and
60+ # names of the three axes; the empty axes is specified by ``'.'``. We manually
61+ # specify the size of the figure, and can make the different axes have
62+ # different sizes by specifying the *width_ratios* and *height_ratios*
63+ # arguments. The *layout* argument is set to ``'constrained'`` to optimize the
64+ # spacing between the axes.
65+
66+ fig , axs = plt .subplot_mosaic ([['histx' , '.' ],
67+ ['scatter' , 'histy' ]],
68+ figsize = (6 , 6 ),
69+ width_ratios = (4 , 1 ), height_ratios = (1 , 4 ),
70+ layout = 'constrained' )
71+ scatter_hist (x , y , axs ['scatter' ], axs ['histx' ], axs ['histy' ])
7972
8073
8174# %%
@@ -109,13 +102,27 @@ def scatter_hist(x, y, ax, ax_histx, ax_histy):
109102
110103# %%
111104#
105+ # While we recommend using one of the two methods described above, there are
106+ # number of other ways to achieve a similar layout:
107+ #
108+ # - The Axes can be positioned manually in relative coordinates using
109+ # `~matplotlib.figure.Figure.add_axes`.
110+ # - A gridspec can be used to create the layout
111+ # (`~matplotlib.figure.Figure.add_gridspec`) and adding only the three desired
112+ # axes (`~matplotlib.figure.Figure.add_subplot`).
113+ # - Four subplots can be created using `~.pyplot.subplots`, and the unused
114+ # axes in the upper right can be removed manually.
115+ # - The ``axes_grid1`` toolkit can be used, as shown in
116+ # :doc:`/gallery/axes_grid1/scatter_hist_locatable_axes`.
117+ #
112118# .. admonition:: References
113119#
114120# The use of the following functions, methods, classes and modules is shown
115121# in this example:
116122#
123+ # - `matplotlib.figure.Figure.subplot_mosaic`
124+ # - `matplotlib.pyplot.subplot_mosaic`
117125# - `matplotlib.figure.Figure.add_subplot`
118- # - `matplotlib.figure.Figure.add_gridspec`
119126# - `matplotlib.axes.Axes.inset_axes`
120127# - `matplotlib.axes.Axes.scatter`
121128# - `matplotlib.axes.Axes.hist`
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