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Apr 18, 2020
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Doc: spines arrows example #17180

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5 changes: 5 additions & 0 deletions examples/axisartist/demo_axisline_style.py
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================

This example shows some configurations for axis style.

Note: The `mpl_toolkits.axisartist` axes classes may be confusing for new
users. If the only aim is to obtain arrow heads at the ends of the axes,
rather check out the :doc:`/gallery/recipes/centered_spines_with_arrows`
example.
"""

from mpl_toolkits.axisartist.axislines import SubplotZero
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35 changes: 35 additions & 0 deletions examples/recipes/centered_spines_with_arrows.py
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"""
===========================
Centered spines with arrows
===========================

This example shows a way to draw a "math textbook" style plot, where the
spines ("axes lines") are drawn at ``x = 0`` and ``y = 0``, and have arrows at
their ends.
"""

import matplotlib.pyplot as plt
import numpy as np


fig, ax = plt.subplots()
# Move the left and bottom spines to x = 0 and y = 0, respectively.
ax.spines["left"].set_position(("data", 0))
ax.spines["bottom"].set_position(("data", 0))
# Hide the top and right spines.
ax.spines["top"].set_visible(False)
ax.spines["right"].set_visible(False)

# Draw arrows (as black triangles: ">k"/"^k") at the end of the axes. In each
# case, one of the coordinates (0) is a data coordinate (i.e., y = 0 or x = 0,
# respectively) and the other one (1) is an axes coordinate (i.e., at the very
# right/top of the axes). Also, disable clipping (clip_on=False) as the marker
# actually spills out of the axes.
ax.plot(1, 0, ">k", transform=ax.get_yaxis_transform(), clip_on=False)
ax.plot(0, 1, "^k", transform=ax.get_xaxis_transform(), clip_on=False)
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Does something like this add arrows on the other ends of the axes, as well? (For when axes are lines instead of only rays)

ax.plot(0, 0, "<k", transform=ax.get_yaxis_transform(), clip_on=False)
ax.plot(0, 0, "vk", transform=ax.get_xaxis_transform(), clip_on=False)

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... Aesthetically, arrows on both ends of each axis are probably what most math teachers are looking for


# Some sample data.
x = np.linspace(-0.5, 1., 100)
ax.plot(x, np.sin(x*np.pi))

plt.show()
3 changes: 3 additions & 0 deletions examples/ticks_and_spines/spine_placement_demo.py
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====================

Adjusting the location and appearance of axis spines.

Note: If you want to obtain arrow heads at the ends of the axes, also check
out the :doc:`/gallery/recipes/centered_spines_with_arrows` example.
"""
import numpy as np
import matplotlib.pyplot as plt
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