我们有时候会面临画带有误差的图，大致长成下面这个样子

image.png

代码为

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

"""

Created on Sun Jul 5 21:12:17 2020

@author: x1c

"""

import matplotlib.pyplot as plt

import seaborn as sns

import numpy as np

sns.set()

#plt.plot(x,(y1+y2)/2,color = 'red')

#plt.fill_between(x, y1, y2, color='red', alpha=0.1)

def plot_error(x,y,label,color='gray'):

# Input y=[y1,y2,...] yi.shape = [m,1]

Y = np.zeros((y[0].shape[0],len(y)))

y_mean = 0

for i in range(len(y)):

y_mean += y[i]

Y[:,i] = y[i][:,0]

#print(Y)

y_mean /= len(y)

y_max = np.max(Y,axis=1)

y_min = np.min(Y,axis=1)

#print(y_max)

x = x.squeeze()

y_mean = y_mean.squeeze()

y_max = y_max.squeeze()

y_min = y_min.squeeze()

plt.plot(x,y_mean,label=label,color=color)

plt.fill_between(x,y_min,y_max,color=color,alpha=0.1)

plt.show()

x = np.arange(0,10)

y1 = x+x**2+(np.random.random(10,)-1/2)*100

y2 = x+x**2+(np.random.random(10,)-1/2)*100

x = x.reshape(-1,1)

y1 = y1.reshape(-1,1)

y2 = y2.reshape(-1,1)

plot_error(x,[y1,y2],label='test',color='gray')

稍加解读，seaborn我们只是用了一下配色，不用是没关系的，只是我觉得这种配色比较美观。

关键的一行代码是plt.fill_between，就是把阴影画出来的关键代码，alpha用来调节其透明度。