matplotlib画图【双坐标轴】

一、导入相关包、设置全局字体

import matplotlib.pyplot as plt
# 设置全局字体
plt.rcParams['font.family'] = 'serif'
plt.rcParams['font.serif'] = ['Times New Roman'] + plt.rcParams['font.serif']

二、创建双坐标轴，合并图例，将图例放在图外

plt.figure()
fig, ax1 = plt.subplots()

# 不同曲线使用不同颜色
cmap=[plt.cm.Paired(i+1) for i in range(10)]

line1 = ax1.plot(x, y, color=cmap[1], label=k)
ax1.set_xlabel('Epoch')
# plt.xticks(rotation=45)
ax1.set_ylabel('left label')

ax2 = ax1.twinx()
line2 = ax2.plot(x, y, color=cmap[2], label=k)
ax2.set_ylabel('right label')

# 合并图例
lines = line1 + line2
labels = [l.get_label() for l in lines]

# 将图例放在图的下面
ax1.legend(lines, labels, bbox_to_anchor=(0.5, -0.25), loc=8, ncol=4)

fig.subplots_adjust(left=0.15, right=0.85, top=0.9, bottom=0.2)
plt.title('Loss and Dice Result')
plt.savefig(save_path)

参考链接：

1. 修改图例显示位置：https://blog.youkuaiyun.com/Caiqiudan/article/details/107747381

2. 修改图例位置后被隐藏/显示不全：https://blog.youkuaiyun.com/Poul_henry/article/details/88311964