带有图例的散点图
还演示了如何通过给alpha值介于0和1之间来调整标记的透明度。
import matplotlib.pyplot as plt
from numpy.random import rand
fig, ax = plt.subplots()
for color in ['red', 'green', 'blue']:
n = 750
x, y = rand(2, n)
scale = 200.0 * rand(n)
ax.scatter(x, y, c=color, s=scale, label=color,
alpha=0.3, edgecolors='none')
ax.legend()
ax.grid(True)
plt.show()