Semi-Circular Waves

Circular_Waves_Code.py

import numpy as np
import matplotlib.animation as animation
from matplotlib import pyplot

hr = 1000
vr = 1000

fig, g = pyplot.subplots(figsize=(hr/100,vr/100))
pyplot.subplots_adjust(top = 0.979, left = 0.024, right = 0.972,  bottom = 0.039)


bkg = "silver"
pyplot.rcParams['axes.facecolor']    = bkg
pyplot.rcParams['savefig.facecolor'] = bkg



fr = 80  # Number of frames

mx   = 0


def update(*args) :
  
  pyplot.clf()
  
  global fig, g, mx
  
 
   
  # Equation - I found the equation here : https://www.desmos.com/calculator/e5xncapcnp
  # am = amplitude
  # n  = Fine tunning
  am = 40
  n = 1.2
  ex1 = np.arange(0+mx,hr+mx)  # mx = "X" movement
  Ey1 = am * np.sqrt( - (2 * np.arcsin( np.sin( (np.pi*ex1)/(2*am) + (n*np.pi) ) ) / np.pi  ) ** 2 + 1) * np.sign( np.cos( (np.pi*ex1)/(2*am) + (n*np.pi) )) 
  Ey1 = Ey1 * 1.2 # More fine tunning 
  

  for p in range(0,len(ex1),8) : # Steps of 8 gave a good visual balance.
 
    pyplot.plot(ex1[p], Ey1[p]+400, color = 'black', linewidth = None,  marker = 'o', ms = 7 )

    pyplot.plot(ex1[p], -Ey1[p]+200, color = 'black', linewidth = None,  marker = 'o', ms = 7 )

 
  
  pyplot.grid(False) 
  pyplot.axis("OFF") 
  
  pyplot.xlim(-4, 601)
  pyplot.ylim(0,600)
    
      
  mx -= 2 # rate of "X" sliding.
              
  return ()



def init() :
        
    return()

o = 1 # Non 1 = single frame - usefull to adjust the plot. 


if o == 1 :


    anim = animation.FuncAnimation(fig, update, init_func=init, blit = True, frames=fr, repeat = False) 
                                      
    sf = 'Circular_Waves.gif'      
    Sname1 = "C://Users//Rober//Desktop//_" + sf    # Mind the directory
    anim.save(Sname1, writer="ffmpeg", fps=24)  
    

else : 
   
    update()