
import matplotlib.pyplot as pltimport numpy as npu=np.linspace(0,4*np.pi,100)v=np.linspace(-2,2,50)U,V=np.meshgrid(u,v)a=0.5X=V*np.cos(U)Y=V*np.sin(U)Z=a*Ufig=plt.figure(figsize=(6,6))ax=fig.add_subplot(111,projection='3d')ax.plot_surface(X,Y,Z,cmap='plasma',alpha=0.8,edgecolor='k')ax.set_title('3D...