CODEWITHSUNDEEP
pythongraphicsmatplotlibplot
static_rtti
static_rtti

Reputation: 56242

In matplotlib, how do you display an axis on both sides of the figure?

I want to draw a plot with matplotlib with axis on both sides of the plot, similar to this plot (the color is irrelevant to this question):

plot

How can I do this with matplotlib?

Note: contrary to what is shown in the example graph, I want the two axis to be exactly the same, and want to show only one graph. Adding the two axis is only to make reading the graph easier.

Upvotes: 28

Views: 67040

Answers (4)

Richard Kopcke
Richard Kopcke

Reputation: 51

The documentation is very helpful. For showing the same y axis ticks and tick labels on both the left side and the right side of a plot, I have had good, consistent results with the following:

ax0 = ax.twinx()
ax0.set_ylim(ax.get_ylim())
ax0.set_yticks(ax.get_yticks(), ax.get_yticklabels(),
               fontsize= 8)

where ax is the default display with y's ticks and tick labels on the left. This first line of code creates ax0 to share the x axis with ax (twinx()). The second line sets the min and max values for ax0's y axis to match those of ax's y axis. The last line sets ax0's y ticks and tick labels to match those of ax.

For two, separate y axes, see John Bartholomew's remarks and references above.

Upvotes: 1

George Crowther
George Crowther

Reputation: 558

I've done this previously using the following:

# Create figure and initial axis    
fig, ax0 = plt.subplots()
# Create a duplicate of the original xaxis, giving you an additional axis object
ax1 = ax.twinx()
# Set the limits of the new axis from the original axis limits
ax1.set_ylim(ax0.get_ylim())

This will exactly duplicate the original y-axis.

Eg:

ax = plt.gca()

plt.bar(range(3), range(1, 4))
plt.axhline(1.75, color="gray", ls=":")

twin_ax = ax.twinx()
twin_ax.set_yticks([1.75])
twin_ax.set_ylim(ax.get_ylim())

enter image description here

Upvotes: 2

kishkin
kishkin

Reputation: 5325

You can use tick_params() (this I did in Jupyter notebook):

import matplotlib.pyplot as plt

bar(range(10), range(10))
tick_params(labeltop=True, labelright=True)

Generates this image:

Bar plot with both x and y axis labeled the same

UPD: added a simple example for subplots. You should use tick_params() with axis object.

This code sets to display only top labels for the top subplot and bottom labels for the bottom subplot (with corresponding ticks):

import matplotlib.pyplot as plt

f, axarr = plt.subplots(2)

axarr[0].bar(range(10), range(10))
axarr[0].tick_params(labelbottom=False, labeltop=True, labelleft=False, labelright=False,
                     bottom=False, top=True, left=False, right=False)

axarr[1].bar(range(10), range(10, 0, -1))
axarr[1].tick_params(labelbottom=True, labeltop=False, labelleft=False, labelright=False,
                     bottom=True, top=False, left=False, right=False)

Looks like this:

Subplots ticks config example

Upvotes: 78

John Bartholomew
John Bartholomew

Reputation: 6586

There are a couple of relevant examples in the online documentation:

Upvotes: 22

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