The measure command allows one to set up a runop (see 4.6) which will identify a measurement point or interval, and evaluate an expression at that point, or call a number of measurement primitives that apply during the interval, such as rise time or pulse width.
measure analysis resultname point | interval [measurements] [postcmds]
measure analysis resultname param=expression [postcmds]
The command will apply, if active, when any circuit is being run. There is also a .measure input syntax element which will set up the measurement on that circuit only. Both use the identical syntax described below. The syntax is based on the .measure statement in HSPICE.
A vector with this name will be added to the current plot, if the measurement is successful. Vector names found in .measure lines are added to the internal save list, guaranteeing that the necessary data will be available when needed, whether or not the vector has been mentioned in a .save line.