1

Given the following: 

import matplotlib.pyplot as plt 
import numpy as np 
#http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.scatter
x = np.random.randn(60) 
y = np.random.randn(60)
x2 = np.random.randn(60)
y2 = np.random.randn(60)

plt.plot(x, y, marker='o', markeredgecolor='r', linestyle='none', markerfacecolor='none')
plt.plot(x2, y2, marker='o', markeredgecolor='r', linestyle='none', markerfacecolor='none')
plt.show()

I'd like for x2 and y2 to be plotted as dashed (or even dotted) circles. I am avoiding the use of plt.scatter because the rest of my script works with plt.plot much better. Here's what I'm looking for: enter image description here

Thanks in advance!

FYI: Here's the actual chart I created. I just used hexagons for now to signify the different data (future data).

enter image description here

The custom legend and plotting over groups of rows in a pandas Data Frame add layers of complexity that I couldn't overcome with plt.scatter.

Stop harming Monica
  • 12,141
  • 1
  • 36
  • 56
Dance Party2
  • 7,214
  • 17
  • 59
  • 106
  • 1
    For that you would have to pass a [`Path`](http://matplotlib.org/api/path_api.html#path) instance as marker. I did not find a way to make a dashed circle. Maybe it is not possible, `scatter` uses additional properties of `PathCollection` for the marker edges. I would say that if you want to plot so many circles that performance is an issue then dashed edges are not the best way to tell some of them apart. Color, sizes or shapes will work much better. – Stop harming Monica Dec 12 '16 at 21:12
  • Can you comment why using scatter is such a big problem? – ImportanceOfBeingErnest Dec 12 '16 at 21:16
  • Sure. I am iterating through a list to plot points from various rows of a data frame. Each row's data is colored based on a list of colors (though this will soon change to a color map). Then I create a custom legend. There are a lot of dependencies and I'm not sure they will work with plt.scatter. See updated question for my example. – Dance Party2 Dec 12 '16 at 21:25

1 Answers1

8

You can use the dotted circle (ur'$\u25CC$') from the STIX font (pdf with all symbols here) using mathtext functionality

 plt.plot(x, y, marker=ur'$\u25CC$', markerfacecolor='r', 
                markeredgecolor='r', markersize=30, linestyle='none', )

Note, that markerfacecolor is set to a color as well.

A drawback is that they need a certain size to be distinguishable from a closed circle.

ImportanceOfBeingErnest
  • 321,279
  • 53
  • 665
  • 712