<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">import matplotlib.pyplot as plt
import numpy as np

N = 100
r0 = 0.6
x = 0.9*np.random.rand(N)
y = 0.9*np.random.rand(N)
area = np.pi*(10 * np.random.rand(N))**2  # 0 to 10 point radii
c = np.sqrt(area)
r = np.sqrt(x*x + y*y)
area1 = np.ma.masked_where(r &lt; r0, area)
area2 = np.ma.masked_where(r &gt;= r0, area)
plt.scatter(x, y, s=area1, marker='^', c=c)
plt.scatter(x, y, s=area2, marker='o', c=c)
# Show the boundary between the regions:
theta = np.arange(0, np.pi/2, 0.01)
plt.plot(r0*np.cos(theta), r0*np.sin(theta))

plt.show()
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