10 Nov
2022
10 Nov
'22
2:25 p.m.
this must have been the issue: # then select only upper portion of 1 + bandwidth equal to period_length ok, uhhhhhhhhhhhh so what is "bandwidth equal to period_length" well, period_length says the period in recording samples that the wave is. meanwhile, fft indices are frequencies in units of 1/bufsize, roughly. so let's think about hte frequencies, roughly. frequency 0 is DC offset. that means its period is infinite. (bufsize / 0) frequency 1 is the first half vs the last half, its period is the entire buffer. (bufsize / 1) the last frequency, bufsize-1, is the nyquist frequency. its period is 2. now what is bufsize? the parameter of interest is the recording buffer size [continue]