编写python程序实现分段函数_如何在Matplotlib中编写分段函数latex代码？

好的，这是解决办法。它包括加载latex mathsymbols包。假设您已在PC中安装了所需的latex软件包。有关详细信息，请参阅MatplotlibRC

代码：#/usr/bin/env python3

# -*- coding: utf-8 -*-

import numpy as np

import matplotlib.pyplot as plt

from matplotlib import rcParams

rcParams['text.latex.unicode'] = True

rcParams['text.usetex'] = True

rcParams['text.latex.preamble'] = '\usepackage{amsthm}', '\usepackage{amsmath}', '\usepackage{amssymb}',

'\usepackage{amsfonts}', '\usepackage[T1]{fontenc}', '\usepackage[utf8]{inputenc}, \usepackage{multicol}'

rcParams['legend.handleheight'] = 3.0

#This fixes the legend line be placed at same height that text legend

def f(x):

return np.piecewise(x, [x < 2.0, x > 2.0], [lambda x: x ** 2.0, lambda x: 4.0])

fig, ax = plt.subplots()

x = np.linspace(-5.0, 5.0, 1000)

ax.axis([x[0], x[-1], x[0], x[-1]])

ax.spines['left'].set_position('center')

ax.spines['right'].set_color('none')

ax.spines['bottom'].set_position('center')

ax.spines['top'].set_color('none')

ax.spines['left']

ax.spines['bottom']

ax.xaxis.set_ticks_position('bottom')

ax.yaxis.set_ticks_position('left')

ticks = []

for i in range(int(x[0]), int(x[-1] + 1), 1):

ticks.append(i)

ticks.remove(0)

ax.set_xticks(ticks)

ax.set_yticks(ticks)

ax.plot(x, f(x), 'b-', 2, 4, 'wo', markeredgecolor='b',

markerfacecolor='w', lw=2.0)

tlegend = r'$f(x)=\left\{\begin{array}{lr} x^2 & : x<2\\ 4 & : x>2\end{array}\right\}$'

ax.legend([tlegend], loc='lower right')

ax.set_title(ur'$Función\; A\; Trozos$') # If you use accents put ur option.

ax.grid('on')

plt.show()

图像：

如果有人知道如何改进下面的代码，我们欢迎：

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