You are reading an old version of the documentation (v2.2.2). For the latest version see
Version 2.2.2
Fork me on GitHub

Related Topics

Lorenz Attractor

This is an example of plotting Edward Lorenz’s 1963 “Deterministic Nonperiodic Flow” in a 3-dimensional space using mplot3d.

Note: Because this is a simple non-linear ODE, it would be more easily
done using SciPy’s ode solver, but this approach depends only upon NumPy.
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

def lorenz(x, y, z, s=10, r=28, b=2.667):
       x, y, z: a point of interest in three dimensional space
       s, r, b: parameters defining the lorenz attractor
       x_dot, y_dot, z_dot: values of the lorenz attractor's partial
           derivatives at the point x, y, z
    x_dot = s*(y - x)
    y_dot = r*x - y - x*z
    z_dot = x*y - b*z
    return x_dot, y_dot, z_dot

dt = 0.01
num_steps = 10000

# Need one more for the initial values
xs = np.empty((num_steps + 1,))
ys = np.empty((num_steps + 1,))
zs = np.empty((num_steps + 1,))

# Set initial values
xs[0], ys[0], zs[0] = (0., 1., 1.05)

# Step through "time", calculating the partial derivatives at the current point
# and using them to estimate the next point
for i in range(num_steps):
    x_dot, y_dot, z_dot = lorenz(xs[i], ys[i], zs[i])
    xs[i + 1] = xs[i] + (x_dot * dt)
    ys[i + 1] = ys[i] + (y_dot * dt)
    zs[i + 1] = zs[i] + (z_dot * dt)

# Plot
fig = plt.figure()
ax = fig.gca(projection='3d')

ax.plot(xs, ys, zs, lw=0.5)
ax.set_xlabel("X Axis")
ax.set_ylabel("Y Axis")
ax.set_zlabel("Z Axis")
ax.set_title("Lorenz Attractor")

Keywords: matplotlib code example, codex, python plot, pyplot Gallery generated by Sphinx-Gallery