You can also use excel for the analysis. I'm not going to math part typing with this phone. PS. I'm not familiar on Rigol scopes, but I would be suprised if there would not be math and analytics functions inbuild.. RMS(mean/integral), phase angle (in cursor menu) and peak value.. etc. Rest of the article looks like using straight forward "frozen phasors" method (right term escaped from my head) in calculationss. The differential and current probes are essential for your safety.