Matplotlib Quiver Plot

Introduction

This lab will guide you through how to create a quiver plot using Matplotlib in Python. A quiver plot displays vector fields as arrows. It is useful in visualizing fluid flows, electric and magnetic fields, and other types of vector fields.

VM Tips

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Sometimes, you may need to wait a few seconds for Jupyter Notebook to finish loading. The validation of operations cannot be automated because of limitations in Jupyter Notebook.

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Skills Graph

Import Libraries

We need to import the numpy and matplotlib libraries to create a quiver plot.

import numpy as np
import matplotlib.pyplot as plt

Create Data

We need to create the X and Y coordinates using the np.meshgrid() function. Then, we create the U and V arrays that represent the vector fields.

X = np.arange(-10, 10, 1)
Y = np.arange(-10, 10, 1)
U, V = np.meshgrid(X, Y)

Create the Quiver Plot

We can create the quiver plot using the ax.quiver() function. We pass in the X, Y, U, and V arrays as parameters.

fig, ax = plt.subplots()
q = ax.quiver(X, Y, U, V)

Create the Quiver Key

We can add a quiver key to the plot to show the scale of the arrows. We use the ax.quiverkey() function to add the key. We pass in the q object, the X and Y position of the key, the length of the arrow, the label for the key, and the position of the label.

ax.quiverkey(q, X=0.3, Y=1.1, U=10,
             label='Quiver key, length = 10', labelpos='E')

Display the Plot

We can display the plot using the plt.show() function.

plt.show()

Summary

In this lab, we learned how to create a quiver plot using Matplotlib in Python. We started by importing the necessary libraries, creating the data, and then creating the quiver plot. Finally, we added a quiver key to the plot and displayed it.