python - How to set ticks on Fixed Position , matplotlib

29
votes

Can anyone help me set the ticks on a fixed position using matplotlib? I've tried using FixedPosition as this tutorial describes:

ax = pl.gca()
ax.xaxis.set_major_locator(eval(locator))

http://scipy-lectures.github.io/intro/matplotlib/matplotlib.html#figures-subplots-axes-and-ticks

But when I try to run, it tells me that set_major_locator method does not exist.

A simple example would be very useful.

Thanks.

2
pythonmatplotlib
That link is a confusing out of context. The use of eval might be very clever for generating their example figures, it is very unclear what the value of locator is. - tacaswell

2 Answers

54
votes

Just use ax.set_xticks(positions) or ax.set_yticks(positions).

For example:

import matplotlib.pyplot as plt

fig, ax = plt.subplots()
ax.set_xticks([0.15, 0.68, 0.97])
ax.set_yticks([0.2, 0.55, 0.76])
plt.show()

enter image description here

9
votes
import numpy as np
import matplotlib.ticker as ticker
import matplotlib.pyplot as plt

name_list = ('Omar', 'Serguey', 'Max', 'Zhou', 'Abidin')
value_list = np.random.randint(0, 99, size = len(name_list))
pos_list = np.arange(len(name_list))

ax = plt.axes()
ax.xaxis.set_major_locator(ticker.FixedLocator((pos_list)))
ax.xaxis.set_major_formatter(ticker.FixedFormatter((name_list)))
plt.bar(pos_list, value_list, color = '.75', align = 'center')

plt.show()