You could do that in 2 different ways 1 FF

Question

< mohamed hassan> You could do that in 2 different ways 1 FFT in ngspice please refer to documentation 2 Run ngspice transient simulation and read the data as a vector in numpy and apply fft on it

mohamed hassan · Answer

I tried to run fft in NGspice for an output signal but it seems to perform the fft for only one value of the signal do you have any idea what may be the issue here

Amro Tork · Answer

< mohamed hassan> What do you mean by one value

Amro Tork · Answer

I personally prefer option 2 run ngspice get the vectors and do whatever I want in Numpy + Scipy

Amro Tork · Answer

< mohamed hassan> such questions < C016HUV935L|analog design> is the right channel for that

Stefan Schippers · Answer

Remember to run the ngspice `linearize` command on vectors you want to export for python fft By default ngspice raw files are not constant time step They are after applying `linearize`

Robin Tsang · Answer

I use option INTERP to get equidistant sample points The period is the time step specified in tran For example in tran 1u 100n the 100n will specify the period of samples