The following code works for dc sweep from 0 to 5v: .dc V2 0 5V 1m But when we run .dc V2 5V 0 1m the simulator doesn't show any error, but it also does says that the variables do not exist, while they were there when run with .dc V2 0 5V 1m Also. .dc V2 5V 0 -1m does not sweep from 5 to 0v, instead sweeps from 0 to 5v. We want to dc sweep 5v to 0v using ngspice. May we please have guidance in that