How to plot parallel coordinates chart in Pandas?

Parallel coordinates chart

Parallel coordinates chart is a graph used to plot individual data points parallel to different performance measures. It allows plotting high-dimensional data into 2-dimensional plots. The data lines are plotted parallel to the x-axis to show other trends in data.

pandas.plotting.parallel_coordinates()

This method is used for parallel coordinates plotting in pandas. It takes different argument values and returns matplotlib.axis.Axes object.

Syntax

#Signature
pandas.plotting.parallel_coordinates(frame,
                                     class_column,
                                     cols=None,
                                     ax=None,
                                     color=None,
                                     use_columns=False,
                                     xticks=None,
                                     colormap=None,
                                     axvlines=True,
                                     axvlines_kwds=None,
                                     sort_labels=False,
                                     **kwargs)

Parameters

It takes multiple argument values but here are listed some mostly used argument values.

• frame: DataFrame as an argument.
• class_column: A string that shows the column name which contains class names.
• cols: Pandas list which contains column names. The default value is None.
• ax: It shows the matplotlib axis instance or object.
• color: It can be a list, tuple, or None. It shows the colors which can be used to differentiate classes.
• use_columns: If it’s set to true the column can be used as xticks.
• xticks: It shows a list or a tuple of values for xticks.

Return value

it returns matplotlib.axis.Axes object.

Explanation

In this section, we’ll implement pandas.plotting.parallel_coordinates() function to plot a parallel coordinate chart.

main.py

# load basic libraries
import pandas as pd
import matplotlib.pyplot as plt
# load employee.csv file as DataFrame
df = pd.read_csv("employee.csv")
# invoking method for plot
pd.plotting.parallel_coordinates( df, 'Name', color=('#556270', '#4ECDC4', '#C7F464'))
# save output as PNG file in output directory
plt.savefig("output/graph.png")

• Line#2-3: Import pandas and matplotlib.pyplot libraries in the program.
• Line#5: pd.read_csv("employee.csv") will read and employee.csv file data and return it as a Python DataFrame.
• Line#7: pd.plotting.parallel_coordinates( df, 'Name', color=('#556270', '#4ECDC4', '#C7F464')) will draw a parallel coordinate plot on runtime.
• Line#9: plt.savefig("output/graph.png") will save the graph as a PNG file in the output directory.

employee.csv

Here, we have a CSV file named employee.csv record including name, medical expenses, bonus, and total.

Name,Medical Expenses,Bonus,TOTAL
Raj,1250,13100,14350
Sharad,1250,2300,3550
Danish,1250,0,1250
Pawan,1250,0,1250
Rijo Paul,1250,2300,3550
Joseph,1250,2300,3550
Aakash,1200,0,1200
Ganesh,1200,0,1200
Vinudas,1250,1500,2750
Divya,800,0,800
Joseph,774,0,774
Sindhu,800,0,800
Deepthi,749,0,749
Lijin,1000,2000,3000

Output