How to Color the Outer Ring in a Radar Plot Based on Column Values

What will you learn?

  • Customize a radar plot to color the outer ring like a doughnut chart.
  • Map data from specific columns to visual attributes in Python radar plots.

Introduction to the Problem and Solution

Visualizing multi-dimensional data effectively is crucial, and radar plots are commonly used for this purpose. In this tutorial, we’ll focus on enhancing radar plots by coloring the outer ring similar to a doughnut chart based on specific column values. By leveraging Python libraries such as Matplotlib and Pandas, we can create visually appealing and informative radar plots.

To tackle this challenge, we will utilize Matplotlib for plotting graphs and charts, specifically working with Radar Charts using its built-in functionalities. Additionally, Pandas will be employed for efficient handling of data structures.


# Import necessary libraries
import pandas as pd
import matplotlib.pyplot as plt

# Sample data (replace this with your dataset)
data = {
    'Category': ['A', 'B', 'C', 'D'],
    'Value': [10, 20, 15, 25],
    'Color': ['red', 'green', 'blue', 'orange']  # Define colors corresponding to categories here

df = pd.DataFrame(data)

# Number of variables/categories present (assuming these are equally spaced)
num_vars = len(df)

# Create Radar Chart
angles = [n / float(num_vars) * 2 * pi for n in range(num_vars)]
angles += angles[:1]

fig, ax = plt.subplots(figsize=(6, 6), subplot_kw=dict(polar=True))
plt.xticks(angles[:-1], df['Category'], color='black')

for i in range(len(df)):
    values += values[:1]

    ax.fill(angles, values, color=df['Color'][i], alpha=0.25)


# Copyright PHD


In this code snippet: – We import Pandas and Matplotlib, essential libraries for data manipulation and visualization. – A sample dataset is created with categories (‘Category’), numerical values (‘Value’), and assigned colors (‘Color’). – The number of categories is determined from the dataset. – Radar chart is created by defining angles based on the number of categories. – Axes are labeled with category names. – Each category’s value is plotted along its respective angle while segment colors are based on pre-defined colors.

    How can I customize the colors assigned to different categories?

    You can specify custom colors by modifying the ‘Color’ column in your dataset or directly setting color codes within your plotting code.

    Can I adjust other visual aspects of the radar plot?

    Yes! You can further customize labels, gridlines, background styles, marker shapes/colors using Matplotlib properties.

    Is it possible to add additional layers or annotations onto the radar plot?

    Absolutely! You can overlay multiple datasets or annotate specific points/regions within your radar plot for enhanced insights.

    Will this method work efficiently for large datasets?

    While suitable for moderate-sized datasets presentation-wise; larger sets might require optimizations regarding performance and readability aspects.

    How flexible is Python when it comes customizing visualizations like these?

    Python offers extensive flexibility through libraries like Matplotlib enabling detailed customization options across various visualization types including radial plots like these doughnut-inspired radars!

    Can I save my customized radar plots as image files?

    Certainly! Matplolib provides functions allowing you tp save generated charts as image files (.png/.jpg) enhancing portability/sharing capabilities.


    This guide has illustrated how to enhance traditional radial plots into engaging representations through simple alterations like coloring rings akin o doughnuts. This knowledge expands possibilities when conveying multivariate information uniquely via Python-based visualization platforms.

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