Python – Elegantly changing the color of a plot frame in matplotlib

colorsmatplotlibpython

This is a kind of follow-up question to this post, where the coloring of axes, ticks and labels was discussed. I hope it is alright to open a new, extended question for this.

Changing the color of a complete frame (ticks and axes) around a double-plot (via add_subplot) with axes [ax1, ax2] results in a lot of code. This snippet changes the color of the frame of the upper plot:

ax1.spines['bottom'].set_color('green')
ax1.spines['top'].set_color('green')
ax1.spines['left'].set_color('green')
ax1.spines['right'].set_color('green')
for t in ax1.xaxis.get_ticklines(): t.set_color('green')
for t in ax1.yaxis.get_ticklines(): t.set_color('green')
for t in ax2.xaxis.get_ticklines(): t.set_color('green')
for t in ax2.yaxis.get_ticklines(): t.set_color('green')

So for changing the frame color of two plots with two y-axes each, I would need 16(!) lines of code… This is how it looks like:

enter image description here

Other methods I dug up so far:

  • matplotlib.rc: discussed here; changes globally, not locally. I want to have some other plots in different colors. Please, no discussions about too many colors in plots… 🙂

    matplotlib.rc('axes',edgecolor='green')

  • dig out the spines of the axis, then change it: also discussed here; not really elegant, I think.

    for child in ax.get_children():
    if isinstance(child, matplotlib.spines.Spine):
        child.set_color('#dddddd')

Is there an elegant way of condensing the above block, something
more "pythonic"?

I'm using python 2.6.5 with matplotlib 0.99.1.1 under ubuntu.

Best Answer

Assuming you're using a reasonably up-to-date version of matplotlib (>= 1.0), perhaps try something like this:

import matplotlib.pyplot as plt

# Make the plot...
fig, axes = plt.subplots(nrows=2)
axes[0].plot(range(10), 'r-')
axes[1].plot(range(10), 'bo-')

# Set the borders to a given color...
for ax in axes:
    ax.tick_params(color='green', labelcolor='green')
    for spine in ax.spines.values():
        spine.set_edgecolor('green')

plt.show()

enter image description here

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