@Steven Bos I can add a function for that. However in general previous point is t-1 not t+1. Consider also that in general timesteps are not uniform. The deriv() function does that difference and divides by the timestep, so using this expression for a graph variable: "Deriv; v(node) deriv()". shows the derivative vs the x-axis (t in transient sims). If useful i can add a kind of diff() function that just does what you are asking. (basically copying the deriv() code and avoiding division by timestep)