3D Surface Plotting with Matplotlib

Introduction

This lab is a step-by-step tutorial on how to plot a 3D surface using Matplotlib in Python. The 3D surface is colored with the coolwarm colormap and made opaque by using "antialiased=False". The tutorial also demonstrates using the .LinearLocator and custom formatting for the z axis tick labels.

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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Import Libraries

import matplotlib.pyplot as plt
import numpy as np

from matplotlib import cm
from matplotlib.ticker import LinearLocator

We import the necessary libraries for the tutorial. Matplotlib is a plotting library for Python that provides an interface similar to MATLAB. Numpy is a fundamental package for scientific computing in Python.

Create Figure and Axes

fig, ax = plt.subplots(subplot_kw={"projection": "3d"})

We create a figure and axes with the subplot_kw parameter set to "projection": "3d". This will create a 3D projection of the plot.

Create Data

X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)

We create the data for the plot. We create the X and Y values as arrays with evenly spaced values from -5 to 5 in increments of 0.25. We then create a meshgrid of X and Y values using np.meshgrid(). We use the meshgrid to calculate the R values, which is the distance from the origin. We then calculate the Z values using the sin() function of R.

Plot the Surface

surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm,
                       linewidth=0, antialiased=False)

We plot the surface using the plot_surface() function. We pass in the X, Y, and Z values as well as the cmap parameter set to cm.coolwarm to color the surface with the coolwarm colormap. We also set linewidth=0 to remove the wireframe and antialiased=False to make the surface opaque.

Customize the Z Axis

ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
## A StrMethodFormatter is used automatically
ax.zaxis.set_major_formatter('{x:.02f}')

We customize the z axis using the set_zlim() function to set the limits of the z axis to -1.01 to 1.01. We then use the set_major_locator() function to set the number of ticks on the z axis to 10 using LinearLocator(10). Finally, we use the set_major_formatter() function to format the z axis tick labels using a StrMethodFormatter.

Add a Color Bar

fig.colorbar(surf, shrink=0.5, aspect=5)

We add a color bar to the plot using the colorbar() function. We pass in the surf object and set shrink=0.5 and aspect=5 to adjust the size of the color bar.

Summary

This tutorial demonstrated how to plot a 3D surface using Matplotlib in Python. We created a figure and axes, created the data, plotted the surface, customized the z axis, and added a color bar. Matplotlib is a powerful tool for creating visualizations in Python.