I want to plot the location of some disks generated randomly on a scatter plot, and see whether the disks are 'connected' to each other. For this, I need to set the radius of each disk fixed/linked to the axis scale.
's' parameter in the
plt.scatter function uses points, so the size is not fixed relative to the axis. If I dynamically zoom into the plot, the scatter marker size remains constant on the plot and does not scale up with the axis.
How do I set the radius so they have a definite value (relative to the axis)?
Best How To :
Instead of using
plt.scatter, I suggest using
patches.Circle to draw the plot (similar to this answer). These patches remain fixed in size so that you can dynamically zoom in to check for 'connections':
import matplotlib.pyplot as plt
from matplotlib.patches import Circle # for simplified usage, import this patch
# set up some x,y coordinates and radii
x = [1.0, 2.0, 4.0]
y = [1.0, 2.0, 2.0]
r = [1/(2.0**0.5), 1/(2.0**0.5), 0.25]
fig = plt.figure()
# initialize axis, important: set the aspect ratio to equal
ax = fig.add_subplot(111, aspect='equal')
# define axis limits for all patches to show
ax.axis([min(x)-1., max(x)+1., min(y)-1., max(y)+1.])
# loop through all triplets of x-,y-coordinates and radius and
# plot a circle for each:
for x, y, r in zip(x, y, r):
The plot this generates looks like this:
Using the zoom-option from the plot window, one can obtain such a plot:
This zoomed in version has kept the original circle size so the 'connection' can be seen.
If you want to change the circles to be transparent,
patches.Circle takes an
alpha as argument. Just make sure you insert it with the call to