I saw the ability to control R by time in someone's drawing, tried it, and it worked fine. Then, I thought that I could use that "time" keyword also to control the voltage of a DC source. However it didn't work. It gives an error:
Error on line 2 : vcc n001 0 time*2 Unknown parameter "time*2" Vcc: Missing value, assumed 0V @ DC .OP point found by inspection.
So, is there an easy way, as easy as it is with the resistor value, to do what I want?