如何使用matplotlib生成阴影区域

Question

我试图在paper中得到数字5，但我无法生成两个阴影区域，指示1 kcal/mol和2 kcal/mol的误差。每个阴影区域必须与纸张颜色不同。我怎样才能做到这一点？

我的代码：

#!/usr/bin/python 
import numpy as np 
import pylab as plot 
import matplotlib.pyplot as plt 
import numpy, scipy, pylab, random 
from matplotlib.ticker import MultipleLocator 
import matplotlib as mpl 
from matplotlib.ticker import MaxNLocator 

color = "#252525" 
gray = "#777777" 

with open("input.txt", "r") as f: 
    x=[] 
    y=[] 
    z=[] 

    for line in f: 
     if not line.strip() or line.startswith('@') or line.startswith('#'): continue 
     row = line.split() 
     x.append(float(row[0])) 
     y.append(float(row[1])) 
     z.append(float(row[2])) 


fig = plt.figure(figsize=(3.2,2.2), dpi=300) 
ax = plt.subplot(111) 


plt.xlim(-2, -12) 
plt.ylim(-2, -12) 
ax.xaxis.set_major_locator(MaxNLocator(6)) 
ax.yaxis.set_major_locator(MaxNLocator(6)) 

ax.xaxis.set_minor_locator(MultipleLocator(1)) 
ax.yaxis.set_minor_locator(MultipleLocator(1)) 

plt.plot(x,y,'o',color="black", ms=3, mec="black") 
plt.plot(x,z, color='gray' , linestyle = "dashed", dashes=(2,2)) 

plt.xlabel('Experimental (kcal/mol)', fontsize=8) 
plt.ylabel('Predicted (kcal/mol)', fontsize=8) 

for axis in ['top','bottom','left','right']: 
    ax.spines[axis].set_linewidth(0.5) 

plt.subplots_adjust(top=0.95) 
plt.subplots_adjust(bottom=0.18) 
plt.subplots_adjust(left=0.14) 
plt.subplots_adjust(right=0.95) 


plt.tick_params(axis='both', which='major', labelsize=7) 
plt.tick_params(axis='both', which='minor', labelsize=0) 

plt.savefig("output.png", dpi=300) 

输入文件：

-2  -2.0 -2 
-3  -3.5 -3 
-4  -5.0 -4 
-5  -7.0 -5 
-6  -6.0 -6 
-8  -10.1 -8 
-10  -10.0 -10 
-12  -12.0 -12 

获得输出：

Answer 1

您正在寻找plt.fill_between。您可以将以下内容添加到您的图中：

plt.plot([-2,-12],[-2,-12], color='gray', linestyle = "dashed", dashes=(2,2)) 
plt.fill_between([-2,-12], [-3,-13], [-1,-11], color='lightblue', alpha=0.5) 
plt.fill_between([-2,-12], [-4,-14], [0,-10], color='lightblue', alpha=0.35) 

这将创建两个填充区域。