Hi Dario, Ok, this looks promising. I have added the below to oscillators.lib. Let me know if you'd like to see any changes. Test results welcome, especially comparisons to the other oscillators, e.g.,
f = 1000; oscs = (os.quadosc(f), os.oscrq(f), os.oscs(f), os.oscq(f)); process = oscs; // study classic corner cases such as those mentioned in https://vicanek.de/articles/QuadOsc.pdf Thanks, - Julius //-----------------`(os.)quadosc`-------------------- // Sinusoidal oscillator based on QuadOsc by Martin Vicanek // // #### Usage // // ``` // quadosc(freq) : _ // ``` // // where // // * `freq`: frequency in Hz // // #### Reference // * <https://vicanek.de/articles/QuadOsc.pdf> //------------------------------------------------------------ // Author: Dario Sanfilippo <sanfilippo.da...@gmail.com> (jos ed.) quadosc(f) = tick ~ (_ , _) with { init = 1-1'; w = 2*ma.PI*f/ma.SR; k1 = tan(.5*w); k2 = 2*k1/(1+k1*k1); tick(u, v) = omega-k1*(v+k2*omega) , v+k2*omega with { omega = (u+init)-k1*v; }; }; On Mon, Jun 17, 2019 at 11:50 AM Dario Sanfilippo <sanfilippo.da...@gmail.com> wrote: > > Hi, Julius. > > I haven't experienced a particular case where this oscillator would be better > than others yet but according to table1 in the aforementioned paper it does > seem to be the best design, doesn't it? I'm not sure it is computationally > heavier than the others. > > Though I have a work which is a self-oscillating FDN with frequency shifters > in the loops that shift the signals of a very small fraction of Hz. For that, > I'd need a very low frequency quadrature oscillator and, according to the > table, Biquad, DWG and QSU would not be accurate for that. > > Cheers, > Dario > > > > On Mon, 17 Jun 2019 at 20:39, Julius Smith <j...@ccrma.stanford.edu> wrote: >> >> Hi Dario, >> >> I don't see its unique advantage(s). Can you make a case for it over >> the oscillators already in oscillators.lib? >> >> Thanks, >> - Julius >> >> On Sat, Jun 15, 2019 at 5:04 AM Dario Sanfilippo >> <sanfilippo.da...@gmail.com> wrote: >> > >> > Described in this paper: https://vicanek.de/articles/QuadOsc.pdf. >> > >> > If I'm not wrong, it's not in the oscillators library yet so it could be a >> > good addition. >> > >> > Cheers, >> > Dario >> > >> > import("stdfaust.lib"); >> > quad_osc(f) = tick ~ (_ , _) >> > with { >> > init = 1-1'; >> > w = 2*ma.PI*f/ma.SR; >> > k1 = tan(.5*w); >> > k2 = 2*k1/(1+k1*k1); >> > tick(u, v) = omega-k1*(v+k2*omega) , v+k2*omega >> > with { >> > omega = (u+init)-k1*v; >> > }; >> > }; >> > process = quad_osc(1000); >> > _______________________________________________ >> > Faudiostream-users mailing list >> > Faudiostream-users@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/faudiostream-users >> >> >> >> -- >> >> Julius O. Smith III <j...@ccrma.stanford.edu> >> Professor of Music and, by courtesy, Electrical Engineering >> CCRMA, Stanford University >> http://ccrma.stanford.edu/~jos/ -- Julius O. Smith III <j...@ccrma.stanford.edu> Professor of Music and, by courtesy, Electrical Engineering CCRMA, Stanford University http://ccrma.stanford.edu/~jos/ _______________________________________________ Faudiostream-users mailing list Faudiostream-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/faudiostream-users
