Python Plotting a graph by taking an input from a .txt file with 1 x axis and 3 y axis?

Question

The text file file :(x range is from 0 to 35) has four columns

x h1 fL0 fR0

I need to plot the 3 functions h1 , fl0 and fR0 in the same graph. I also need normalise x values by dividing by the maximum. So that all x values in both files range from 0 to 1 .

But i need help in taking the input from the text file and plotting them ,

The sample text is -

0 0 2.64834E-76 2.538822025

0.343137255 7.09437E-16 1.4726E-75 0.643489985

0.68627451 1.50251E-15 8.1884E-75 0.163099011

1.37254902 3.73658E-15 2.53178E-73 0.010477807

2.058823529 7.79212E-15 7.82801E-72 0.000673115

The code I have written is ---

import matplotlib.pyplot as plt

import csv

 x = []

 y = []

 z = []

 q = []

with open('c1.txt','r') as csvfile:

plots = csv.reader(csvfile, delimiter=' ')

for row in plots:

    x.append((row[0]))

    y.append((row[1]))

    z.append((row[2]))

    q.append((row[3]))

plt.plot(x,y, label='h1')

pl.plot(x,z, label='fL0')

p1.plot(x,q, label='fR0')

plt.xlabel('x')

plt.ylabel('y')

plt.title('Interesting Graph\nCheck it out')

plt.legend()

plt.show()

The problem from this code is :IndexError : list index out of range

Answer 1

Try this.

import matplotlib.pyplot as plt

For easier reading and manipulating of the data I use the pandas library.

import pandas as pd

Read the data

data = pd.read_csv('c1.txt', delimiter=' ')

Re-label the columns and normalise for x

data.columns = ['x', 'h1', 'fL0', 'fR0']
data['xnorm'] = data.x / max(data.x)

Create the plot

fig, ax1 = plt.subplots()
ax1.plot(data.xnorm, data.h1, color='red')
ax2 = ax1 
ax2.plot(data.xnorm, data.fL0, color='blue')
ax3 = ax1
ax3.plot(data.xnorm, data.fR0, color='green')
plt.title('Interesting Graph\nCheck it out')
plt.legend()
plt.show()