填充两条垂直线之间的区域

使用 fill_betweenx 在两条曲线之间的水平方向上着色.

import matplotlib.pyplot as plt
import numpy as np

y = np.arange(0.0, 2, 0.01)
x1 = np.sin(2 * np.pi * y)
x2 = 1.2 * np.sin(4 * np.pi * y)

fig, [ax1, ax2, ax3] = plt.subplots(1, 3, sharey=True, figsize=(6, 6))

ax1.fill_betweenx(y, 0, x1)
ax1.set_title('between (x1, 0)')

ax2.fill_betweenx(y, x1, 1)
ax2.set_title('between (x1, 1)')
ax2.set_xlabel('x')

ax3.fill_betweenx(y, x1, x2)
ax3.set_title('between (x1, x2)')

现在填充满足逻辑条件的 x1 和 x2 之间的区域.请注意,这与调用以下代码不同:

fill_between(y[where], x1[where], x2[where])

因为在多个连续区域上存在边缘效应.

fig, [ax, ax1] = plt.subplots(1, 2, sharey=True, figsize=(6, 6))
ax.plot(x1, y, x2, y, color='black')
ax.fill_betweenx(y, x1, x2, where=x2 >= x1, facecolor='green')
ax.fill_betweenx(y, x1, x2, where=x2 <= x1, facecolor='red')
ax.set_title('fill_betweenx where')

# Test support for masked arrays.
x2 = np.ma.masked_greater(x2, 1.0)
ax1.plot(x1, y, x2, y, color='black')
ax1.fill_betweenx(y, x1, x2, where=x2 >= x1, facecolor='green')
ax1.fill_betweenx(y, x1, x2, where=x2 <= x1, facecolor='red')
ax1.set_title('regions with x2 > 1 are masked')

此示例说明了一个问题:由于数据网格化,在交叉点处存在不需要的未填充三角形.一种蛮力解决方案是在绘图之前将所有数组插值到一个非常精细的网格中.

plt.show()

标签: plot-type: fill_between level: beginner