For loop for charting in Python

Question

I want to create a chart with a for loop. X-axis is plotted correctly and even y-axis scale is set correctly, but no actual line chart is created. What could be wrong with the code below?

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib

test = {'date':[2012, 2013, 2014, 2015],'val':[9,15,12,20]}

test_df=pd.DataFrame(data=test)

test_df=test_df.set_index('date')

fig, ax = plt.subplots(figsize=(25,25))

for i in range(0, len(test_df)):
    
    ax.plot(test_df.index[i], test_df['val'].iloc[i], color='blue', linewidth=10)
        
plt.show()

ted · Accepted Answer · 2021-01-10 17:36:54Z

1

You could either plot the whole series with:

ax.plot(test_df.index, test_df['val'], color='blue', linewidth=10)

and no for loop

Or plot the points themselves with:

ax.plot(test_df.index[i], test_df['val'].iloc[i], "b+", linewidth=10)

See matplotlib's markers for individual points markers

answered Jan 10, 2021 at 17:36

ted

14.9k10 gold badges70 silver badges117 bronze badges

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

1 Comment

PRA Over a year ago

Thank you, this solved the issue for me! "b+" didn't work itself, but other markers did.

Kaan Berke UĞURLAR · Accepted Answer · 2021-01-10 17:40:38Z

1

Yo do not give coordinates to plot a line which leads us to plot a scatter plot.

for i in range(0, len(test_df)): 
    ax.scatter(test_df.index[i], test_df['val'].iloc[i], color='blue', linewidth=10)

As far as I'm concerned, this would solve your problem but if you really want to connect those dots then you might give it a shot without a for loop:

ax.plot(test_df.index, test_df['val'], color='blue', linewidth=10)

answered Jan 10, 2021 at 17:40

Kaan Berke UĞURLAR

1226 bronze badges

Collectives™ on Stack Overflow

For loop for charting in Python

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related