olli's seems easier for me to code, and better than csound's huh? thanks
2016-06-23 11:27 GMT-03:00 Matt Barber <[email protected]>: > csound's hilbert transform is also 6th-order. Code here: > > > https://github.com/csound/csound/blob/2ec0073f4bb55253018689a19dd88a432ea6da46/Opcodes/ugsc.c > > On Thu, Jun 23, 2016 at 9:16 AM, katja <[email protected]> wrote: > >> Attached is a zip with test patch for [olli~] and [hilbert~] so you >> can compare and also check with different sample rates. It seems that >> Olli's coefficients are optimized to work well from 20 Hz up at 44K1 >> sample rate, and Pd's built-in from 80 Hz up. They both work at other >> samples rates too, but with different range. >> >> Since the coefficients for x[n-2] and y[n-2] are non-zero in the >> biquads, the maximum phase shift is as large as in any 2nd order >> section, therefore I think the four sections together are 8 order >> equivalent indeed. >> >> By the way, the abstraction in my first response wasn't completely >> vanilla-compatible, this is fixed in current attachment (for anyone >> else interested). >> >> Katja >> >> On Thu, Jun 23, 2016 at 6:24 AM, Alexandre Torres Porres >> <[email protected]> wrote: >> > Awesome, I can code it based on that :) but which order is it? >> > >> > I see it has 4 biquads, but it doesnt look like an 8th order because >> some >> > coefficients are zeroed out, so I'm confused. >> > >> > Another question, does it work at any sample rate? This question is also >> > aimed to pd's hilbert~ abstraction by the way. >> > >> > cheers >> > >> > 2016-06-22 17:27 GMT-03:00 katja <[email protected]>: >> >> >> >> Hi, Olli Niemitalou has coefficients published for a higher order >> >> 'hilbert transformer' on http://yehar.com/blog/, attached is [olli~] >> >> abstraction based on it. >> >> >> >> Katja >> >> >> >> On Wed, Jun 22, 2016 at 4:37 AM, Alexandre Torres Porres >> >> <[email protected]> wrote: >> >> > Howdy, I'm working on a frequency shifter object (via single sideband >> >> > modulation / complex modulation). >> >> > >> >> > In Max they have a so called "6th order hilbert transformer with a >> >> > minimum >> >> > of error". In Pd, the hilbert~ abstraction is 4th order. I'm copying >> the >> >> > pd >> >> > abstraction for now, but I was hoping to use such a higher order >> filter >> >> > and >> >> > also use- but I can't find a source for such a formula. Any help >> finding >> >> > it? >> >> > >> >> > thanks >> >> > >> >> > _______________________________________________ >> >> > [email protected] mailing list >> >> > UNSUBSCRIBE and account-management -> >> >> > https://lists.puredata.info/listinfo/pd-list >> >> > >> > >> > >> >> _______________________________________________ >> [email protected] mailing list >> UNSUBSCRIBE and account-management -> >> https://lists.puredata.info/listinfo/pd-list >> >> >
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