plot_esferas

This is a short hack to use spheres as markers in matplotlib scatter plots in python. The approach may be extended to use any arbitrary image as a marker. I mimicked some of the usual options of plot().

The main idea was borrowed/taken/(your-choice-of-words) from: http://matplotlib.1069221.n5.nabble.com/custom-markers-from-images-tp4166p4173.html

The "new" colormap for yellow spheres is from http://schubert.atmos.colostate.edu/~cslocum/custom_cmap.html

I put this together in a small function for easy use, and added it as a method to matplotlib Axes. I am sharing it in case somebody else finds it useful.

I am sure that there are many better ways to obtain the same result, and I'll be really very glad to learn about them.

What does it do?

A picture is worth a thousand ...

and then two: 2000 ...

Changing the style looks nice too ...

How to use it?

The use it is pretty simple. Just call the method: ax.plot_esfera

There are two scripts showing how to use it simple_example_1.py and simple_example_2.py. They are something similar to this:

import numpy as np
import matplotlib.pyplot as plt
import plt_esfera

fig= plt.figure(figsize=(12,9))
ax= fig.add_subplot(111, aspect='auto')

x= np.linspace(0.1,10,31)
y= 1.5*(1+ np.sin(x)/(.01+x))
y1= y
for c in plt_esfera.colores.keys():
  if len(c) > 1:
    y1 -= .2
    ax.plot_esfera( x,y1, color=c, markersize=14, label=c)

# Plot a simple "standard" line
ax.plot(x,2+(.5+x)*y/(1+x)**2,'-k',lw=3, label='Line 1')
#
ax.legend(loc='best', numpoints=1)
plt.show()

Does it need improving?

Yes, they are several unresolved issues. Foremost, it would be really nice to have the spheres appearing (atutomatically) in the legend when using labels. Currently a circle with a similar color will be shown.

If you have suggestions/comments please contact me.