"""Original lens sketch; Python 3.14, root numpy/matplotlib dependencies. Writes PNG basename to caller CWD, respecting caller MPLCONFIGDIR. """ import numpy as np import matplotlib matplotlib.use('Agg') import matplotlib.pyplot as plt th=np.linspace(0,2*np.pi,1001) t=np.linspace(0,np.pi/2,501) fig,ax=plt.subplots(figsize=(6,6),dpi=120,facecolor='white');ax.set_facecolor('white') ax.plot(np.cos(th),np.sin(th),color='#91a8b4',linewidth=1.2) ax.plot(1+np.cos(th),1+np.sin(th),color='#bba999',linewidth=1.2) arc0=np.column_stack([np.cos(t),np.sin(t)]) arc1=np.column_stack([1-np.cos(t),1-np.sin(t)]) lens=np.vstack([arc0,arc1]) ax.fill(lens[:,0],lens[:,1],facecolor='#dbeef5',edgecolor='none') ax.plot(arc0[:,0],arc0[:,1],color='#18567b',linewidth=2.4) ax.plot(arc1[:,0],arc1[:,1],color='#a36332',linewidth=2.4) ax.scatter([1,0],[0,1],s=48,facecolors='white',edgecolors='#333333',zorder=4) ax.text(1.06,-.12,'1',fontsize=12);ax.text(-.12,1.08,'i',fontsize=12) ax.plot([0,1],[0,1],'.',color='#555555') ax.text(-.15,-.15,'0');ax.text(1.04,1.08,'1+i') ax.text(.5,.5,'A',ha='center',va='center',fontsize=16) ax.axhline(0,color='#dddddd',linewidth=.7);ax.axvline(0,color='#dddddd',linewidth=.7) ax.set(xlim=(-1.15,2.15),ylim=(-1.15,2.15),xlabel='Re z',ylabel='Im z',title='Intersection of two open unit discs') ax.set_aspect('equal');fig.tight_layout();fig.savefig('paper-1-circular-lens.png',facecolor='white',transparent=False);plt.close(fig)