In [1]:
import numpy as np
import scipy as sc
from moviepy.editor import VideoClip
from vispy import app, scene
from vispy.gloo.util import _screenshot
from IPython.display import clear_output, Image, display
In [2]:
n = 7
alpha = 6
zero = sc.special.jn_zeros(n,alpha)[alpha-1]
duration = 64*np.pi/zero
print(zero,duration)

28.1911884595 7.13208420137
In [3]:
X, Y = np.linspace(-1.024,1.024,256), np.linspace(-1.024,1.024,256)
In [4]:
XX, YY = np.meshgrid(X,Y)
In [5]:
RR = (XX**2+YY**2)**(0.5)
PP = np.arctan2(XX,YY)
ZZ = lambda t: sc.special.jn(n,zero*RR)*np.cos(n*PP)*np.cos(zero*t/32.0)*np.heaviside(1-RR,0)
In [6]:
canvas = scene.SceneCanvas(keys='interactive', bgcolor='w')
view = canvas.central_widget.add_view()
view.camera = scene.TurntableCamera(up='z', fov=60)
In [7]:
surface = scene.visuals.SurfacePlot(x=X, y=Y, z= ZZ(0),shading='smooth', color=(0.5, 0.5, 1, 1))
view.add(surface)
canvas.show()
In [8]:
def make_frame(t):
    surface.set_data(z = ZZ(t))
    canvas.on_draw(None)
    return _screenshot((0,0,canvas.size[0],canvas.size[1]))[:,:,:3]
In [10]:
animation = VideoClip(make_frame, duration=duration).resize(width=1024)
animation.write_gif("bessel_mode.gif", fps=20)

[MoviePy] Building file bessel_mode.gif with imageio

100%|██████████| 143/143 [02:50<00:00,  1.19s/it]
In [11]:
clear_output(wait = True)
display(Image(url='bessel_mode.gif'))