Basic radar chart


A radar chart displays the value of several numerical variables for one or several entities. This post aims to show how to draw a basic radar chart using the basic functions of matplotlib.

In order to build a basic radar chart, we can use the basic functions of matplotlib. Here is an example of a simple one, displaying the values of 5 variables for only one individual. The input data is a pandas data frame where each line represents an individual, and each column a variable. See graph #391 and #392 to see how to represent several individuals.

# Libraries
import matplotlib.pyplot as plt
import pandas as pd
from math import pi
 
# Set data
df = pd.DataFrame({
'group': ['A','B','C','D'],
'var1': [38, 1.5, 30, 4],
'var2': [29, 10, 9, 34],
'var3': [8, 39, 23, 24],
'var4': [7, 31, 33, 14],
'var5': [28, 15, 32, 14]
})
 
# number of variable
categories=list(df)[1:]
N = len(categories)
 
# We are going to plot the first line of the data frame.
# But we need to repeat the first value to close the circular graph:
values=df.loc[0].drop('group').values.flatten().tolist()
values += values[:1]
values
 
# What will be the angle of each axis in the plot? (we divide the plot / number of variable)
angles = [n / float(N) * 2 * pi for n in range(N)]
angles += angles[:1]
 
# Initialise the spider plot
ax = plt.subplot(111, polar=True)
 
# Draw one axe per variable + add labels
plt.xticks(angles[:-1], categories, color='grey', size=8)
 
# Draw ylabels
ax.set_rlabel_position(0)
plt.yticks([10,20,30], ["10","20","30"], color="grey", size=7)
plt.ylim(0,40)
 
# Plot data
ax.plot(angles, values, linewidth=1, linestyle='solid')
 
# Fill area
ax.fill(angles, values, 'b', alpha=0.1)

# Show the graph
plt.show()

Barplot

Spider / Radar

Wordcloud

Parallel

Lollipop

Circular Barplot

Contact & Edit

👋 This document is a work by Yan Holtz. Any feedback is highly encouraged. You can fill an issue on Github, drop me a message onTwitter, or send an email pasting yan.holtz.data with gmail.com.

This page is just a jupyter notebook, you can edit it here. Please help me making this website better 🙏!

Violin

Density

Histogram

Boxplot

Ridgeline

Scatterplot

Heatmap

Correlogram

Bubble

Connected Scatter

2D Density

Barplot

Spider / Radar

Wordcloud

Parallel

Lollipop

Circular Barplot

Treemap

Venn Diagram

Donut

Pie Chart

Dendrogram

Circular Packing

Line chart

Area chart

Stacked Area

Streamgraph

Map

Choropleth

Hexbin

Cartogram

Connection

Bubble

Chord Diagram

Network

Sankey

Arc Diagram

Edge Bundling

Colors

Interactivity

Animation with python

Animation

Cheat sheets

Caveats

3D