python - 手动设置图例中点的颜色

Question

我正在制作一个如下所示的散点图:

(问题底部的 MWE)

如上图所示，matplotlib 自动将图例中点的颜色设置为蓝色。我需要将此点设置为颜色图中不存在的其他颜色(即:黑色)，这样它们就不会与与所述颜色图关联的颜色产生混淆。

我环顾四周，但 matplotlib.legend模块似乎不接受 color 关键字。有没有办法做到这一点？

---

这是 MWE:

import matplotlib.pyplot as plt
import numpy as np

def rand_data():
    return np.random.uniform(low=0., high=1., size=(100,))

# Generate data.
x, y, x2, x3 = [rand_data() for i in range(4)]
# This data defines the markes and labels used.
x1 = np.random.random_integers(7, 9, size=(100,))

# Order all lists so smaller points are on top.
order = np.argsort(-np.array(x2))
# Order x and y.
x_o, y_o = np.take(x, order), np.take(y, order)
# Order list related to markers and labels.
z1 = np.take(x1, order)
# Order list related to sizes.
z2 = np.take(x2, order)
# Order list related to colors.
z3 = np.take(x3, order)

plt.figure()
cm = plt.cm.get_cmap('RdYlBu')

# Scatter plot where each value in z1 has a different marker and label
# assigned.
mrk = {7: ('o', '7'), 8: ('s', '8'), 9: ('D', '9')}
for key, value in mrk.items():

    s1 = (z1 == key)
    plt.scatter(x_o[s1], y_o[s1], marker=value[0], label=value[1],
        s=z2[s1] * 100., c=z3[s1], cmap=cm, lw=0.2)

# Plot colorbar
plt.colorbar()

# Plot legend.
plt.legend(loc="lower left", markerscale=0.7, scatterpoints=1, fontsize=10)

plt.show()

Answer 1

您可以获取图例句柄并单独更改它们的颜色:

ax = plt.gca()
leg = ax.get_legend()
leg.legendHandles[0].set_color('red')
leg.legendHandles[1].set_color('yellow')