如何将matplotlib图重新缩放到文本？

Question

I would like to be able to autoscale a matplotlib figure to make arbitrarily placed text annotations visible. This is a challenge since artists other than Patches and Lines are not included in relim. For instance, the following text is out of the viewing area.

fig = figure()
ax = fig.add_subplot(111)
t = matplotlib.text.Text(10,10, 'Hello')
ax.add_artist(t)
show()

The docs cryptically mention using update_datalim_numerix , but how do I determine the correct bounding box in data units? Is there a method that will tell me the text bounding box size? How do I cope with an artist that has been subjected to multiple transformations?

Answer 1

You can place your text relative to the axis, as explained here :

import matplotlib.pyplot as plt
import matplotlib.text as txt

fig = plt.figure()
ax = fig.add_subplot(111)
t = txt.Text(0.5,0.5, 'Hello',transform=ax.transAxes)
ax.add_artist(t)
plt.show()

This example will place your text always at the center of the plot, no matter how you change the axis.