Why set_xticks doesn't set the labels of ticks?

Question

import matplotlib.pyplot as plt

x = range(1, 7)
y = (220, 300, 300, 290, 320, 315)

def test(axes):
    axes.bar(x, y)
    axes.set_xticks(x, [i+100 for i in x])

fig, (ax1, ax2) = plt.subplots(1, 2)
test(ax1)
test(ax2)

enter image description here

I am expecting the xlabs as 101, 102 ... However, if i switch to use plt.xticks(x, [i+100 for i in x]) and rewrite the function explicitly, it works.

My guess is because in your code set_xticks is getting a generator object, not a list. Try `list([i+100 for i in x)]` instead. — rabs, Feb 20 '14 at 14:55
@rabs there is no generator involved, they are both lists, I am using python 2 — colinfang, Feb 20 '14 at 15:00

score 145 · Accepted Answer · edited Aug 23 '17 at 09:06

145

.set_xticks() on the axes will set the locations and set_xticklabels() will set the displayed text.

def test(axes):
    axes.bar(x,y)
    axes.set_xticks(x)
    axes.set_xticklabels([i+100 for i in x])

enter image description here

edited Aug 23 '17 at 09:06

Shihe Zhang

2,641
5
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answered Feb 20 '14 at 15:12

Hooked

84,485
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2

@RichardRast and it's still appears to be weird. – trolley813 Jun 14 '17 at 15:59
3

plt.xticks(position, label) works while set_xticks on axis like subplots doesnt and one needs another call set_xticklabels. i call bad api on pyplot – droid192 Jan 31 '19 at 09:35
`axes.set_xticklabels` did the trick – seralouk Oct 20 '21 at 11:47
NB : axes can be accessed with `plt.gca()`. – Skippy le Grand Gourou Oct 11 '22 at 16:27
@SkippyleGrandGourou: but if I do `plt.gca().set_xticks(...)` it has no effect? – Joseph Garvin May 17 '23 at 04:10
1

Ah my problem was I called `xscale` after which blew away the ticks – Joseph Garvin May 18 '23 at 14:03

score 9 · Answer 2 · answered Jan 06 '19 at 22:28

9

Another function that might be useful, if you don't want labels for every (or even any) tick is axes.tick_params.

def test(axes):
    axes.tick_params(axis='x',which='minor',direction='out',bottom=True,length=5)

answered Jan 06 '19 at 22:28

groceryheist

1,538
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score 5 · Answer 3 · answered Dec 08 '21 at 09:36

5

New in matplotlib 3.5.0

ax.set_xticks now accepts a labels param to set ticks and labels simultaneously:

fig, ax = plt.subplots()
ax.bar(x, y)
ax.set_xticks(x, labels=[i + 100 for i in x])
#                ^^^^^^

Since changing labels usually requires changing ticks, the labels param has been added to all relevant tick functions for convenience:

ax.xaxis.set_ticks(..., labels=...)
ax.yaxis.set_ticks(..., labels=...)
ax.set_xticks(..., labels=...)
ax.set_yticks(..., labels=...)

answered Dec 08 '21 at 09:36

tdy

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What if you're just using the plt.foo commands and don't have an ax object? – Joseph Garvin May 17 '23 at 04:05
@JosephGarvin Then you can get the ax object manually via `ax = plt.gca()` – tdy May 17 '23 at 04:33
added a new comment there, issue was I called xscale after – Joseph Garvin May 18 '23 at 14:04

Why set_xticks doesn't set the labels of ticks?

3 Answers3

New in matplotlib 3.5.0

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