Hi!

This is roughly the translation of the above Julia code to Python:

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import numpy as np

import matplotlib.pyplot as plt

from matplotlib.animation import FuncAnimation

from datetime import datetime

# Define the curve parameters

n = 200

t = np.linspace(0, 6 * np.pi, n)

def f(t):

return t * np.cos(t)

def g(t):

return t * np.sin(t)

def h(t):

return t

def f1(t):

return np.cos(t) - t * np.sin(t)

def f2(t):

return -2 * np.sin(t) - t * np.cos(t)

def g1(t):

return np.sin(t) + t * np.cos(t)

def g2(t):

return 2 * np.cos(t) - t * np.sin(t)

def h1(t):

return 1

def h2(t):

return 0

x = f(t)

y = g(t)

z = h(t)

# Graphical Parameters

molt = 3.0

limx = [np.min(x) - 1, np.max(x) + 1]

limy = [np.min(y) - 1, np.max(y) + 1]

limz = [np.min(z) - 1, np.max(z) + 2]

cam_height = 30

cam_angle = np.linspace(0, 90, num=len(t))

# Create the animation

fig = plt.figure()

ax = fig.add_subplot(111, projection='3d')

def update(i):

ax.clear()

ax.plot(x, y, z, label="Curve")

draw_trihedron(ax, t[i], i, molt)

ax.set_xlim(limx)

ax.set_ylim(limy)

ax.set_zlim(limz)

ax.view_init(elev=cam_angle[i], azim=0)

print(f"{int(100 * i / len(t))}% -> ")

def draw_trihedron(ax, t, i, molt):

trihedron_size = molt

trihedron = np.array([[0, 0, 0],

[trihedron_size, 0, 0],

[0, trihedron_size, 0],

[0, 0, trihedron_size]])

R = np.array([[f1(t), g1(t), h1(t)],

[f2(t), g2(t), h2(t)],

[0, 0, 1]])

trihedron_rotated = trihedron.dot(R.T)

ax.plot(trihedron_rotated[:, 0], trihedron_rotated[:, 1], trihedron_rotated[:, 2], color='r')

ani = FuncAnimation(fig, update, frames=len(t), interval=100)

plt.show()

# Save the animation as a GIF

now = datetime.now().strftime("%Y-%m-%d_%H:%M:%S")

ani.save(f"{now}.gif", writer='imagemagick', fps=15)

print("END!")

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You need to install numpy and matplotlib to run the above code:

pip install matplotlib numpy

Also you may need imagemagick or ffmpeg:

sudo apt-get install imagemagick

sudo apt-get install ffmpeg