Using Proxy Artist to make legend

Community matplotlib-users
1

Hello,

I have made a plot with a fill_between part, which does not show up in the
legend. I have read that I have to use a proxy artist for this, but I have no
clue where to place this, and how.. The fill between works fine, it's just the
legend that is not really cooperating :wink:

import matplotlib.pyplot as plt

plt.plot(dbx, gemlist)
plt.title('Reekslengte '+str(i))
plt.xlabel('signaal-ruisverhouding ingangssignaal (dB)')
plt.ylabel('signaal-ruisverhouding uitgangssignaal (dB)')
plt.xlim(-36, 22)

plt.fill_between(dbx, boven, onder, color='b', alpha=0.1)
plt.legend(loc=4)
plt.show()

Tnx in advance :slight_smile:

Sabine

2

I have a convenience function (copied below) in my python path that I like to use for this purpose.

Hope that helps,
-Tony

···

On Thu, Jan 26, 2012 at 8:20 AM, Sabine van der Linden <info@…3936…> wrote:

Hello,

I have made a plot with a fill_between part, which does not show up in the

legend. I have read that I have to use a proxy artist for this, but I have no

clue where to place this, and how… The fill between works fine, it’s just the

legend that is not really cooperating :wink:

import matplotlib.pyplot as plt

plt.plot(dbx, gemlist)

plt.title('Reekslengte '+str(i))

plt.xlabel(‘signaal-ruisverhouding ingangssignaal (dB)’)

plt.ylabel(‘signaal-ruisverhouding uitgangssignaal (dB)’)

plt.xlim(-36, 22)

plt.fill_between(dbx, boven, onder, color=‘b’, alpha=0.1)

plt.legend(loc=4)

plt.show()

Tnx in advance :slight_smile:

Sabine

#~~~~

def fill_between(x, y1, y2=0, ax=None, **kwargs):

"""Plot filled region between `y1` and `y2`.

This function works exactly the same as matplotlib's fill_between, except
that it also plots a proxy artist (specifically, a rectangle of 0 size)

so that it can be added it appears on a legend.
"""
ax = ax if ax is not None else plt.gca()
ax.fill_between(x, y1, y2, **kwargs)
p = plt.Rectangle((0, 0), 0, 0, **kwargs)

ax.add_patch(p)
return p