Python-将多个文本文件中的一列数据绘制成单个图表

Question

我对 Python 很陌生

尝试从多个相似文件中绘制一列数据(见下文)

#0  Date-time:  20/02/2015 22:50            
#1  Recorder:   35X1078         
#2  File type:  0           
#3  Columns:    7           
#4  Channels:   4           
#5  Field separation:   1           
#6  Decimal point:  1           
#7  Date def.:  0   2       
#8  Time def.:  0           
#9  Channel 1:  Temperature(°C) Temp(°C)    3   1
#10 Channel 2:  Depth(m)    Depth(m)    2   2
#11 Reconvertion:   0           
#14 Channel 3:  Pitch(°)    Pitch(°)    1   1
#18 Channel 4:  Roll(°) Roll(°) 1   1
#19 Line color: 1   2   3   4
1 20-02-15 12:00:00 8.615 -2.64 92.3 88.8                   
2 20-02-15 12:00:01 8.615 -2.64 92.1 89.1                   
3 20-02-15 12:00:02 8.615 -2.64 92.1 87.2                   
4 20-02-15 12:00:03 8.615 -2.64 92.6 89.6                   
5 20-02-15 12:00:04 8.615 -2.64 91.9 91.5                   
6 20-02-15 12:00:05 8.615 -2.64 91.9 88.7                   
7 20-02-15 12:00:06 8.615 -2.64 92.1 89.7                   
8 20-02-15 12:00:07 8.615 -2.64 92.5 87.2                   
9 20-02-15 12:00:08 8.615 -2.66 92.1 87.6                   
10 20-02-15 12:00:09 8.615 -2.64 92.9 87.4  

数据有许多要忽略的标题行并忽略第一列

我绘制单个文件的代码是:

import matplotlib.pyplot as plt
import pandas as pd
import sys


print 'loading & plotting: '+sys.argv[1]+'.txt'
data=pd.read_csv(sys.argv[1]+'.txt',delimiter='\s',skiprows=17,names=['index','date','time','temp','pressure','pitch','roll'],infer_datetime_format=True)

fig,axes = plt.subplots(4,1)
data.plot('time','temp',ax=axes[0])
axes[0].set_ylabel('temperature $^\circ$C')
data.plot('time','pressure',ax=axes[1])
axes[1].set_ylabel('pressure (Bar)')
data.plot('time','pitch',ax=axes[2])
axes[2].set_ylabel('pitch $^\circ$')
data.plot('time','roll',ax=axes[3])
axes[3].set_ylabel('roll $^\circ$')
fig.suptitle('Data from Star Oddi pitch + roll sensor X1078: %s'%(data['date'][0]))

fig.savefig('X1078_uimage.png',bbox_inches='tight')
plt.show()

我知道我的图表布局很垃圾，我可以自己整理，但我现在想将多个文件绘制到同一个图表上。

Answer 1

您只需在更改数据时在循环内重复绘图调用，但将图形创建和保存保留在循环之外。

如果您经常处理文件列表，glob 模块又好又简单。

from glob import glob
import matplotlib.pyplot as plt

files = glob("*.txt")
fig, ax = plt.subplots()

for f in files:
    print("Current file is"+f)
    #your csv loading into data   
    data.plot('time','temp',ax=axes[0])   

#outside of the for loop
plt.savefig("myplots.png")