Python - Plot one column of data from multiple text files into single graph

Question

I am very new to Python

Trying to plot one column of data from multiple similar files (see below)

#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

Data has a number of header rows to be ignored and ignore first column

My code for plotting a single file is:

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()

I know the layout of my graphs is rubbish, I can tidy that myself, but I now want to plot multiple files on to the same graphs.

agomcas · Accepted Answer · 2015-03-02 13:53:47Z

1

You just need to repeat plot calls inside a loop while changing your data, but leaving the figure creation and saving out of the loop.

If you often deal with lists of files, glob module is good and easy.

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")

answered Mar 2, 2015 at 13:53

agomcas

7055 silver badges12 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Python - Plot one column of data from multiple text files into single graph

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related