If you simulate circuits that include not only analog, but also digital or switching/PWM aspects, then you know that traditional “AC” or frequency-domain analysis cannot be used for these designs.

It includes design entry and schematic capture, time- and frequency-domain simulation and analysis, physical layout with automated device-level placement and routing and integrated design-rule checker ...

Modern oscilloscopes capture, view, measure, and analyze complex RF signals in the time, frequency, and modulation domains. Time-domain analysis, the original oscilloscope function, allows users to ...