Skip to content

DOC: add example of labelling axes #20147

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 7, 2021
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
70 changes: 70 additions & 0 deletions examples/text_labels_and_annotations/label_subplots.py
Original file line number Diff line number Diff line change
@@ -0,0 +1,70 @@
"""
==================
Labelling subplots
==================

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.
"""

import matplotlib.pyplot as plt
import matplotlib.transforms as mtransforms

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

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()

##############################################################################
# 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)']],
constrained_layout=True)

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()

##############################################################################
# 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)']],
constrained_layout=True)

for label, ax in axs.items():
ax.set_title('Normal Title', fontstyle='italic')
ax.set_title(label, fontfamily='serif', loc='left', fontsize='medium')

plt.show()

#############################################################################
#
# .. admonition:: References
#
# The use of the following functions, methods, classes and modules is shown
# in this example:
#
# - `matplotlib.figure.Figure.subplot_mosaic` /
# `matplotlib.pyplot.subplot_mosaic`
# - `matplotlib.axes.Axes.set_title`
# - `matplotlib.axes.Axes.text`
# - `matplotlib.transforms.ScaledTranslation`