print a warning when plotting current

            plt.legend(handles=[energyhandle, meanhandle])

            plt.ylabel("Voltage [V]")

        elif opt["plot"] == "I":

            print("Warning: The current reported by energytrace is aggressively smoothed and often inaccurate.")

            # nA

            (energyhandle,) = plt.plot(

                data[1:, 0] * 1e-6, data[1:, 1] * 1e-9, "b-", label="I", markersize=1