Strange output from running .meas xx four 1K v(x)? Maybe you should output the amplitude first and then the phase. And a question with the sign of the amplitude.
The output is Cartesian coordinates, (real, imag).
What does that have to do with (real, imag). This is not an AC analysis. It’s a TRAN analysis. I’d prefer (amplitude, phase).
.four is computing the Fourier component, which is complex.
I tried using .meas H1 Four … , .meas H2 Four … and .meas H3 Four … to get the amplitudes and then plot the amplitudes.
But as it turns out this feature is missing. Using .meas X Four is useless! I will not use this “program feature” anymore.