Draw Vertical Lines in Python 3D Plot

In this tutorial, you’ll learn how to draw vertical lines in 3D plots using the Python Matplotlib library.

We’ll cover generating data points, plotting single and multiple vertical lines, and adding color gradients.

 

 

Generate Data Points for Vertical Lines

To create vertical lines in a 3D plot, you first need to generate the data points.

You can use NumPy to create arrays for the x, y, and z coordinates.

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

# Generate data points for a vertical line
x = np.array([2])
y = np.array([3])
z = np.linspace(0, 10, 100)
print(f"x: {x}")
print(f"y: {y}")
print(f"z: {z[:5]}...")

Output:

x: [2]
y: [3]
z: [0.        0.1010101 0.2020202 0.3030303 0.4040404]...

The x and y coordinates are fixed, while z varies from 0 to 10 with 100 points.

 

Using plot3D()

You can use the plot3D() function from Matplotlib to draw a vertical line in a 3D plot.

Here’s how to create a simple vertical line:

fig = plt.figure(figsize=(10, 8))
ax = fig.add_subplot(111, projection='3d')
ax.plot3D(x, y, z, 'r-')
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
ax.set_zlabel('Z-axis')
ax.set_title('Vertical Line in 3D Plot')
plt.show()

Output:

The plot shows a red vertical line starting at (2, 3, 0) and ending at (2, 3, 10).

 

Draw multiple vertical lines

To draw multiple vertical lines, you can create arrays with multiple x and y coordinates.

Here’s how to draw three vertical lines:

x = np.array([1, 3, 5])
y = np.array([2, 4, 6])
z = np.linspace(0, 10, 100)
fig = plt.figure(figsize=(10, 8))
ax = fig.add_subplot(111, projection='3d')
for i in range(len(x)):
    ax.plot3D([x[i]] * len(z), [y[i]] * len(z), z, '-')
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
ax.set_zlabel('Z-axis')
ax.set_title('Multiple Vertical Lines in 3D Plot')
plt.show()

Output:

The plot displays three vertical lines at different x and y positions, each extending from z=0 to z=10.

 

Add a color gradient to vertical lines

You can enhance the visual appeal of your vertical lines by adding a color gradient.

Use a colormap to do this effect:

x = np.array([2, 4, 6])
y = np.array([3, 5, 7])
z = np.linspace(0, 10, 100)
fig = plt.figure(figsize=(10, 8))
ax = fig.add_subplot(111, projection='3d')
for i in range(len(x)):
    colors = plt.cm.viridis(z / 10)
    ax.scatter3D([x[i]] * len(z), [y[i]] * len(z), z, c=colors, s=10)
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
ax.set_zlabel('Z-axis')
ax.set_title('Vertical Lines with Color Gradient in 3D Plot')
plt.show()

Output:

The plot shows three vertical lines using scattered points, with colors transitioning from blue at the bottom to yellow at the top.