曲线条件颜色下的Matplotlib区域

Question

我尝试这样填充两个线条图之间的区域：

import matplotlib.pyplot as plt
import numpy as np


ROCE = np.array([-7.0,-14.0,-11.0,8.0,7.0,17.0,10.0,9.0])
WACC = np.array([4.5, 5.1, 4.7, 3.4, 2.9, 3.7, 3.6, 3.9])
YEAR = np.array([2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019])

fig, ax = plt.subplots(1,1)
ax.plot(YEAR, ROCE, color = 'blue')
ax.plot(YEAR, WACC, color = 'black')
ax.fill_between(YEAR, ROCE, WACC, where=ROCE >= WACC, facecolor='green')
ax.fill_between(YEAR, ROCE, WACC, where=ROCE <= WACC, facecolor='red')

然而，我有一个问题，在点的线交叉，可以看到在附加的图像。我想我必须对线点进行插值。你知道怎么解决这个问题吗？

谢谢!

Plot

Answer 1

默认情况下，fill_between仅查看给定值。但它还可以选择插值，以找到where参数的确切交叉点。

import matplotlib.pyplot as plt
import numpy as np

ROCE = np.array([-7.0,-14.0,-11.0,8.0,7.0,17.0,10.0,9.0])
WACC = np.array([4.5, 5.1, 4.7, 3.4, 2.9, 3.7, 3.6, 3.9])
YEAR = np.array([2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019])

fig, ax = plt.subplots(1,1)
ax.plot(YEAR, ROCE, color = 'blue')
ax.plot(YEAR, WACC, color = 'black')
ax.fill_between(YEAR, ROCE, WACC, where=ROCE >= WACC, interpolate=True, facecolor='green')
ax.fill_between(YEAR, ROCE, WACC, where=ROCE <= WACC, interpolate=True, facecolor='red')
plt.show()

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