On 11/18/13, Tom Rondeau <t...@trondeau.com> wrote: > On Mon, Nov 18, 2013 at 8:22 AM, Robert James <srobertja...@gmail.com> > wrote: >> On 11/18/13, Marcus Müller <mar...@hostalia.de> wrote: >>> Hi Robert! >>> >>> This is strange -- but could be explained by the fact that numerical >>> inaccuracy don't allow us to *exactly* recreate all values during >>> fft-ifft >>> operation. >>> Also, make sure you use a rectangular window. >> >> Wow, switching to a rectangular window of fft_size solved it! I'm >> baffled: I know windows are a way of pretransforming the wave prior to >> FFT, to eliminate artifacts. I just used the default window. Why did >> I need a rectangular window here? In what other cases do I need it? > > Were both windows the same or different? I've often seen people trying > this experiment using a window on the forward FFT but no window on the > inverse FFT. That would obviously cause different output results.
Both were the same - the default blackmanharris, set to the ftt_len size _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
