matplotlib.pyplot标签设置

import numpy as np
import matplotlib.pyplot as mp
# 数据源（三角函数） ----------------------------------------
x = np.linspace(-np.pi, np.pi, 999)
cos_y = np.cos(x)
sin_y = np.sin(x) / 2
# 设置坐标范围 ----------------------------------------
mp.xlim(x.min() * 1.1, x.max() * 1.1)
mp.ylim(min(cos_y.min(), sin_y.min()) * 1.1,
        max(cos_y.max(), sin_y.max()) * 1.1)
# 设置坐标轴刻度标签 ----------------------------------------
mp.xticks(
    [-np.pi, -np.pi / 2, np.pi / 2, np.pi],
    [r'$-\pi$', r'$-\frac{\pi}{2}$', r'$\frac{\pi}{2}$', r'$\pi$']
)
mp.yticks([-1, 0, 1])
# 将矩形坐标轴改成十字坐标轴 ----------------------------------------
# 获取当前坐标轴对象
ax = mp.gca()
# 将垂直坐标刻度置于左边框
ax.yaxis.set_ticks_position('left')
# 将左边框置于数据坐标原点
ax.spines['left'].set_position(('data', 0))
# 将水平坐标刻度置于底边框
ax.xaxis.set_ticks_position('bottom')
# 将底边框置于数据坐标原点
ax.spines['bottom'].set_position(('data', 0))
# 将右边框和顶边框设置成无色
ax.spines['right'].set_color('none')
ax.spines['top'].set_color('none')

设置标签

# 设置标签名称【label】
mp.plot(x, cos_y, linestyle='-', linewidth=1,color='dodgerblue',
        label=r'$y=cos(x)$')
mp.plot(x, sin_y, linestyle='-', linewidth=1,color='orangered',
        label=r'$y=\frac{1}{2}sin(x)$')
# 设置标签位置【loc】
mp.legend(loc='upper left')
# 显示图形
mp.show()