import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1) #这个是只有一个图的情形 可加参数figsize=(6, 4)

ax.plot(x_1,y_1,color=(0/255,0/255,0/255),marker='s',markersize=10,label='label_1')
ax.plot(x_2,y_2,color=(100/255,29/255,161/255),marker='^',markersize=10,label='label_2')
ax.plot(x_3,y_3,color=(0/255, 51/255, 102/255),marker='D',markersize=10,label='label_3')
ax.plot(x_4,y_4,color=(163/255, 11/255, 25/255),marker='o',markersize=10,label='label_4')
ax.legend()
#ax.set_ylim((-50,1500))
ax.set_xlabel('xlabel')
ax.set_ylabel('ylabel')



#以下代码是添加一个放大的子图，一般绘图不需要
from mpl_toolkits.axes_grid1.inset_locator import mark_inset
from mpl_toolkits.axes_grid1.inset_locator import inset_axes

axins = inset_axes(ax, width="40%", height="30%",loc='center', #子图的大小和位置
                   bbox_to_anchor=(0, 0, 1, 1), #别动吧。。。
                   bbox_transform=ax.transAxes)
axins.plot(x_3,y_3,color=(0/255, 51/255, 102/255),marker='D',markersize=10,label='label_3')
axins.plot(x_4,y_4,color=(163/255, 11/255, 25/255),marker='o',markersize=10,label='label_4')
zone_left = 10   #需要放大的区间
zone_right = 14
x_ratio = 0.5
y_ratio = 0.5
x=dims
y_1=np.array(y_3)
y_2=np.array(y_4)

xlim0 = x[zone_left]-(x[zone_right]-x[zone_left])*x_ratio
xlim1 = x[zone_right]+(x[zone_right]-x[zone_left])*x_ratio
y = np.hstack((y_1[zone_left:zone_right], y_2[zone_left:zone_right]))
ylim0 = np.min(y)-(np.max(y)-np.min(y))*y_ratio
ylim1 = np.max(y)+(np.max(y)-np.min(y))*y_ratio
axins.set_xlim(xlim0, xlim1)
axins.set_ylim(ylim0, ylim1)
# loc1 loc2: 坐标系的四个角
# 1 (右上) 2 (左上) 3(左下) 4(右下)
mark_inset(ax, axins, loc1=3, loc2=1, fc="none", ec='k', lw=1)


plt.savefig('figures.pdf')#dpi=500
plt.show()

import matplotlib.pyplot as plt
plt.rcParams["mathtext.fontset"] = "cm"  #指定字符集，这个字符集更全
plt.rcParams["text.usetex"] =True  #开启使用latex编译

plt.title(r'$a+b=c$')