Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
420 views
in Technique[技术] by (71.8m points)

python matplotlib dash-dot-dot - how to?

I am using python and matplotlib to generate graphical output.
Is there a simple way to generate a dash-dot-dot line-style?
I am aware of the '--', '-.', and ':' options. Unfortunately, '-..' does not result in a dash-dot-dot line.
I have looked at the set_dashes command, but that seems to control the length of the dashes and the space between two adjacent dashes.
One option may be to plot two lines on top of each other; one dashed with ample space between the dashes - and one dotted, with the dots as large as the dashes are wide and spaced so that two dots are in between each of the dashes. I do not doubt this can be done, I am simply hoping for an easier way.
Did I overlook an option?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can define custom dashes:

import matplotlib.pyplot as plt

line, = plt.plot([1,5,2,4], '-')
line.set_dashes([8, 4, 2, 4, 2, 4]) 
plt.show()

enter image description here

[8, 4, 2, 4, 2, 4] means

  • 8 points on, (dash)
  • 4 points off,
  • 2 points on, (dot)
  • 4 points off,
  • 2 points on, (dot)
  • 4 points off.

@Achim noted you can also specify the dashes parameter:

plt.plot([1,5,2,4], '-', dashes=[8, 4, 2, 4, 2, 4])
plt.show()

produces the same result shown above.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...