How to Plot a Histogram in Python Using Matplotlib with List Data

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By squashlabs, Last Updated: October 16, 2023

How to Plot a Histogram in Python Using Matplotlib with List Data

To plot a histogram in Python using Matplotlib with list data, you can follow these steps:

Step 1: Import the necessary libraries

To get started, you need to import the necessary libraries: Matplotlib and NumPy. Matplotlib is a widely-used plotting library in Python, while NumPy provides support for efficient numerical operations.

import matplotlib.pyplot as plt
import numpy as np

Related Article: Python Scikit Learn Tutorial

Step 2: Generate random data

Next, you can generate some random data to use for plotting the histogram. For example, let’s say we have a list of 1000 values between 0 and 100:

data = np.random.randint(0, 100, 1000)

Step 3: Plot the histogram

Now, you can use Matplotlib’s hist function to plot the histogram. The hist function takes the data and bins as input parameters. Bins represent the intervals in which the data will be divided in the histogram.

plt.hist(data, bins=10)
plt.show()

This will create a histogram with 10 bins.

Step 4: Customize the histogram

You can further customize the histogram by adding labels, titles, changing the color, and adjusting other properties. Here’s an example:

plt.hist(data, bins=10, color='skyblue', edgecolor='black')
plt.xlabel('Value')
plt.ylabel('Frequency')
plt.title('Histogram of Random Data')
plt.show()

This will create a histogram with a sky blue color, black edges, and labeled axes.

Alternative approach using Pandas

Another way to plot a histogram in Python is by using the Pandas library, which provides high-level data manipulation and analysis tools. Here’s an alternative approach using Pandas:

import pandas as pd

# Create a DataFrame from the list data
df = pd.DataFrame(data, columns=['Values'])

# Plot the histogram using Pandas
df['Values'].plot.hist(bins=10, color='skyblue', edgecolor='black')
plt.xlabel('Value')
plt.ylabel('Frequency')
plt.title('Histogram of Random Data')
plt.show()

This approach allows you to directly plot the histogram from a Pandas DataFrame, which can be useful if you are working with tabular data.

Best practices for plotting histograms

When plotting histograms in Python, it’s important to consider the following best practices:

1. Choose an appropriate number of bins: The number of bins determines the granularity of the histogram. Too few bins can oversimplify the distribution, while too many bins can make it difficult to interpret. Experiment with different bin sizes to find the optimal balance.

2. Label your axes: Always label the x-axis and y-axis of the histogram to provide clear information about the data being plotted. This helps viewers understand the meaning of the histogram and interpret the distribution correctly.

3. Title your histogram: Add a clear and descriptive title to your histogram to provide context and summarize the purpose of the plot. This helps viewers quickly grasp the main idea behind the histogram.

4. Customize the appearance: Use different colors, edgecolors, and other properties to customize the appearance of the histogram according to your preference or to match the overall style of your visualization.

5. Consider alternative visualization techniques: Histograms are suitable for exploring the distribution of a single variable. However, if you want to compare distributions or visualize relationships between variables, consider using other types of plots, such as box plots, scatter plots, or bar charts.