How to Display Hours on the X-Axis in a Line Plot

What will you learn?

Discover how to effectively customize the x-axis of a line plot in Python to showcase hours for enhanced time-series data visualization.

Introduction to the Problem and Solution

When working with time-series data that involves hourly intervals, presenting hours on the x-axis can significantly improve the interpretability of plots. By tailoring the x-axis ticks and labels, we can create visually appealing and informative visualizations. This tutorial delves into leveraging Python to achieve this customization effortlessly.

Code

import matplotlib.pyplot as plt
import pandas as pd

# Sample data for demonstration purposes
hours = range(24)
data = [5, 7, 10, 8, 12, 15, 18, 20, 17, 14,
        12, 9 ,11 ,13 ,16 ,19 ,21 ,23 ,22 ,18,
        15 ,13 ,10]

# Plotting the data with hours on the x-axis
plt.figure(figsize=(10,6))
plt.plot(hours, data)
plt.xlabel('Hours')
plt.ylabel('Data Values')
plt.xticks(range(0,len(hours),2), ['{}:00'.format(hour) for hour in range(0,len(hours),2)])
plt.title('Data vs Time')
plt.grid(True)
plt.show()

# Copyright PHD

Code credits: PythonHelpDesk.com

Explanation

  • Import Libraries: Import matplotlib.pyplot for plotting and pandas (optional for this example).
  • Sample Data: Define sample hourly data values.
  • Plotting: Create a line plot using plt.plot(), set labels with xlabel() and ylabel().
  • Customizing X-Axis Ticks: Utilize xticks() method to set custom tick locations and labels based on hours.
    How do I change the interval between displayed hours?

    To adjust the interval between displayed hours on the x-axis ticks:

    plt.xticks(range(0,len(hours),4), ['{}:00'.format(hour) for hour in range(0,len(hours),4)])
    
    # Copyright PHD

    Can I display minutes along with hours?

    Certainly. You can format your x-tick labels accordingly by modifying their generation within xticks().

    How can I rotate or adjust the angle of tick labels?

    To rotate or adjust tick label angles:

    plt.xticks(rotation=45) # Adjust rotation angle as needed.
    
    # Copyright PHD

    Is it possible to display AM/PM alongside hours?

    Yes. Customize your tick labels like ‘{} AM’.format(hour) or use conditional statements based on time of day.

    What if my dataset spans multiple days? How do I handle that?

    For datasets spanning multiple days while displaying hourly information only:

    total_hours = days * len(hours)
    # Update xticks accordingly...
    
    # Copyright PHD

    Can I change other properties of axis labels like font size or color?

    Absolutely. Utilize additional parameters within functions such as xlabel(), e.g., fontsize, color.

    Conclusion

    In this tutorial, we explored how to enhance line plots by incorporating specific hourly intervals on the x-axis. This level of customization not only improves visualization clarity but also aids in better understanding time-based datasets. For further exploration…

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