Dec 10, 2023 · May 17, 2023
diff --git a/galleries/examples/text_labels_and_annotations/label_subplots.py b/galleries/examples/text_labels_and_annotations/label_subplots.py
 Labelling subplots
 ==================

 Labelling subplots is relatively straightforward, and varies,
 so Matplotlibdoes not have a general method for doing this.
 Labelling subplots is relatively straightforward, and varies, so Matplotlib
 does not have a general method for doing this.

 Simplest is putting the label inside the axes.  Note, here
 we use `.pyplot.subplot_mosaic`, and use the subplot labels
 as keys for the subplots, which is a nice convenience.  However,
 the same method works with `.pyplot.subplots` or keys that are
 different than what you want to label the subplot with.
 We showcase two methods to position text at a given physical offset (in
 fontsize units or in points) away from a corner of the Axes: one using
 `~.Axes.annotate`, and one using `.ScaledTranslation`.

 For convenience, this example uses `.pyplot.subplot_mosaic` and subplot
 labels as keys for the subplots.  However, the approach also works with
 `.pyplot.subplots` or keys that are different than what you want to label the
 subplot with.
 """

 import matplotlib.pyplot as plt

 import matplotlib.transformsas mtransforms
 from matplotlib.transformsimport ScaledTranslation

 # %%
 fig, axs = plt.subplot_mosaic([['a)', 'c)'], ['b)', 'c)'], ['d)', 'd)']],
                              layout='constrained')

 for label, ax in axs.items():
    # label physical distance in and down:
    trans = mtransforms.ScaledTranslation(10/72, -5/72, fig.dpi_scale_trans)
    ax.text(0.0, 1.0, label, transform=ax.transAxes + trans,
            fontsize='medium', verticalalignment='top', fontfamily='serif',
            bbox=dict(facecolor='0.7', edgecolor='none', pad=3.0))

 plt.show()
    # Use Axes.annotate to put the label
    # - at the top left corner (axes fraction (0, 1)),
    # - offset half-a-fontsize right and half-a-fontsize down
    #   (offset fontsize (+0.5, -0.5)),
    # i.e. just inside the axes.
    ax.annotate(
        label,
        xy=(0, 1), xycoords='axes fraction',
        xytext=(+0.5, -0.5), textcoords='offset fontsize',
        fontsize='medium', verticalalignment='top', fontfamily='serif',
        bbox=dict(facecolor='0.7', edgecolor='none', pad=3.0))

 # %%
 # We may prefer the labels outside the axes, but still aligned
 # with each other, in which case we use a slightly different transform:

 fig, axs = plt.subplot_mosaic([['a)', 'c)'], ['b)', 'c)'], ['d)', 'd)']],
                              layout='constrained')

 for label, ax in axs.items():
    # label physical distance to the left and up:
    trans = mtransforms.ScaledTranslation(-20/72, 7/72, fig.dpi_scale_trans)
    ax.text(0.0, 1.0, label, transform=ax.transAxes + trans,
            fontsize='medium', va='bottom', fontfamily='serif')

 plt.show()
    # Use ScaledTranslation to put the label
    # - at the top left corner (axes fraction (0, 1)),
    # - offset 20 pixels left and 7 pixels up (offset points (-20, +7)),
    # i.e. just outside the axes.
    ax.text(
        0.0, 1.0, label, transform=(
            ax.transAxes + ScaledTranslation(-20/72, +7/72, fig.dpi_scale_trans)),
        fontsize='medium', va='bottom', fontfamily='serif')

 # %%
 # If we want it aligned with the title, either incorporate in the title or
 # use the *loc* keyword argument:

 fig, axs = plt.subplot_mosaic([['a)', 'c)'], ['b)', 'c)'], ['d)', 'd)']],
                              layout='constrained')

 for label, ax in axs.items():
    ax.set_title('Normal Title', fontstyle='italic')
    ax.set_title(label, fontfamily='serif', loc='left', fontsize='medium')
 #    - `matplotlib.figure.Figure.subplot_mosaic` /
 #      `matplotlib.pyplot.subplot_mosaic`
 #    - `matplotlib.axes.Axes.set_title`
 #    - `matplotlib.axes.Axes.text`
 #    - `matplotlib.transforms.ScaledTranslation`
 #    - `matplotlib.axes.Axes.annotate`
Original file line number	Diff line number	Diff line change
Expand Up		@@ -3,54 +3,58 @@
		Labelling subplots
		==================

		Labelling subplots is relatively straightforward, and varies,
		so Matplotlibdoes not have a general method for doing this.
		Labelling subplots is relatively straightforward, and varies, so Matplotlib
		does not have a general method for doing this.

		Simplest is putting the label inside the axes. Note, here
		we use `.pyplot.subplot_mosaic`, and use the subplot labels
		as keys for the subplots, which is a nice convenience. However,
		the same method works with `.pyplot.subplots` or keys that are
		different than what you want to label the subplot with.
		We showcase two methods to position text at a given physical offset (in
		fontsize units or in points) away from a corner of the Axes: one using
		`~.Axes.annotate`, and one using `.ScaledTranslation`.

		For convenience, this example uses `.pyplot.subplot_mosaic` and subplot
		labels as keys for the subplots. However, the approach also works with
		`.pyplot.subplots` or keys that are different than what you want to label the
		subplot with.
		"""

		import matplotlib.pyplot as plt

		import matplotlib.transformsas mtransforms
		from matplotlib.transformsimport ScaledTranslation

		# %%
		fig, axs = plt.subplot_mosaic([['a)', 'c)'], ['b)', 'c)'], ['d)', 'd)']],
		layout='constrained')

		for label, ax in axs.items():
		# label physical distance in and down:
		trans = mtransforms.ScaledTranslation(10/72, -5/72, fig.dpi_scale_trans)
		ax.text(0.0, 1.0, label, transform=ax.transAxes + trans,
		fontsize='medium', verticalalignment='top', fontfamily='serif',
		bbox=dict(facecolor='0.7', edgecolor='none', pad=3.0))

		plt.show()
		# Use Axes.annotate to put the label
		# - at the top left corner (axes fraction (0, 1)),
		# - offset half-a-fontsize right and half-a-fontsize down
		# (offset fontsize (+0.5, -0.5)),
		# i.e. just inside the axes.
		ax.annotate(
		label,
		xy=(0, 1), xycoords='axes fraction',
		xytext=(+0.5, -0.5), textcoords='offset fontsize',
		fontsize='medium', verticalalignment='top', fontfamily='serif',
		bbox=dict(facecolor='0.7', edgecolor='none', pad=3.0))

		# %%
		# We may prefer the labels outside the axes, but still aligned
		# with each other, in which case we use a slightly different transform:

		fig, axs = plt.subplot_mosaic([['a)', 'c)'], ['b)', 'c)'], ['d)', 'd)']],
		layout='constrained')

		for label, ax in axs.items():
		# label physical distance to the left and up:
		trans = mtransforms.ScaledTranslation(-20/72, 7/72, fig.dpi_scale_trans)
		ax.text(0.0, 1.0, label, transform=ax.transAxes + trans,
		fontsize='medium', va='bottom', fontfamily='serif')

		plt.show()
		# Use ScaledTranslation to put the label
		# - at the top left corner (axes fraction (0, 1)),
		# - offset 20 pixels left and 7 pixels up (offset points (-20, +7)),
		# i.e. just outside the axes.
		ax.text(
		0.0, 1.0, label, transform=(
		ax.transAxes + ScaledTranslation(-20/72, +7/72, fig.dpi_scale_trans)),
		fontsize='medium', va='bottom', fontfamily='serif')

		# %%
		# If we want it aligned with the title, either incorporate in the title or
		# use the loc keyword argument:

		fig, axs = plt.subplot_mosaic([['a)', 'c)'], ['b)', 'c)'], ['d)', 'd)']],
		layout='constrained')

		for label, ax in axs.items():
		ax.set_title('Normal Title', fontstyle='italic')
		ax.set_title(label, fontfamily='serif', loc='left', fontsize='medium')
Expand All		@@ -67,5 +71,4 @@
		# - `matplotlib.figure.Figure.subplot_mosaic` /
		# `matplotlib.pyplot.subplot_mosaic`
		# - `matplotlib.axes.Axes.set_title`
		# - `matplotlib.axes.Axes.text`
		# - `matplotlib.transforms.ScaledTranslation`
		# - `matplotlib.axes.Axes.annotate`