python - 两个函数之间的填充区域

Question

import matplotlib.pyplot as plt
import numpy as np

def domain():
    x = np.arange(0, 10, 0.001)

    f1 = lambda x: (2*x - x**2)**0.5
    plt.plot(x, f1(x), label = '$y = \sqrt{2x - x^2}$')
    plt.plot(f1(x), x, label = '$x = \sqrt{2y - y^2}$')
    plt.xlabel('X')
    plt.ylabel('Y')
    plt.legend(loc='best')


    axes = plt.gca()
    axes.set_xlim([0, 5])
    axes.set_ylim([0, 5])
    plt.show()

domain()

如何使用 fill_between()填充两条线之间的区域？换句话说，如何填充绿线和蓝线之间的小花瓣？

Answer 1

@user 5061 在代码上是正确的，反函数在那里关闭

import matplotlib.pyplot as plt
import numpy as np

def domain():
    x = np.arange(0, 10, 0.001)

    f1 = lambda x: (2*x - x**2)**0.5
    f2 = lambda x: 1 - (1-x*x)**0.5 # other part is f2 = lambda x: 1 + (1-x*x)**0.5
    plt.plot(x, f1(x), label = '$y = \sqrt{2x - x^2}$')
    plt.plot(f1(x), x, label = '$x = \sqrt{2y - y^2}$')
    plt.fill_between(x, f1(x), f2(x), where=f1(x)>=f2(x), interpolate=True, color='yellow')
    plt.xlabel('X')
    plt.ylabel('Y')
    plt.legend(loc='best')


    axes = plt.gca()
    axes.set_xlim([0, 5])
    axes.set_ylim([0, 5])
    plt.show()

domain()

不采用正分量 1 + (1-x*x)**0.5 因为它不影响交集。