莫烦-matplotlib学习笔记（四）

参考莫烦教学视频https://morvanzhou.github.io/tutorials/data-manipulation/plt/2-5-lagend/

import matplotlib.pyplot as pltimport numpy as npx = np.linspace(-3, 3, 50)y1 = 2*x + 1y2 = x**2plt.figure()# set x limitsplt.xlim((-1, 2))plt.ylim((-2, 3))# set new sticksnew_sticks = np.linspace(-1, 2, 5)plt.xticks(new_sticks)# set tick labelsplt.yticks([-2, -1.8, -1, 1.22, 3],           [r'$really\ bad$', r'$bad$', r'$normal$', r'$good$', r'$really\ good$'])#设置两条线的类型等信息（蓝色实线与红色虚线).l1, = plt.plot(x, y1, label='linear line')l2, = plt.plot(x, y2, color='red', linewidth=1.0, linestyle='--', label='square line')plt.legend(loc='best')# plt.legend(handles=[l1, l2], labels=['up', 'down'],  loc='best')# the "," is very important in here l1, = plt... and l2, = plt... for this step"""legend( handles=(line1, line2, line3),           labels=('label1', 'label2', 'label3'),           'upper right')    The *loc* location codes are::          'best' : 0,          (currently not supported for figure legends)          'upper right'  : 1,          'upper left'   : 2,          'lower left'   : 3,          'lower right'  : 4,          'right'        : 5,          'center left'  : 6,          'center right' : 7,          'lower center' : 8,          'upper center' : 9,          'center'       : 10,"""plt.show()