Sorry, you don't need 2^256 bits, my brain was just getting warmed up and I got ahead of myself there. There are 2^256 different SORNs in this scenario and you need 256 bits to represent them all. But the point stands that if you actually want good precision (2^32 different values, for instance), the SORN concept quickly becomes untenable.
-Ethan On Fri, Apr 15, 2016 at 9:03 AM, Ethan Fenn <et...@polyspectral.com> wrote: > I really don't think there's a serious idea here. Pure snake oil and > conspiracy theory. > > Notice how he never really pins down one precise encoding of unums... > doing so would make it too easy to poke holes in the idea. > > For example, this idea of SORNs is presented, wherein one bit represents > the presence or absence of a particular value or interval. Which is fine if > you're dealing with 8 possible values. But if you want a number system that > represents 256 different values -- seems like a reasonable requirement to > me! -- you need 2^256 bits to represent a general SORN. Whoops! But of > course he bounces on to a different topic before the obvious problem comes > up. > > -Ethan > > > > On Fri, Apr 15, 2016 at 4:38 AM, Marco Lo Monaco <marco.lomon...@teletu.it > > wrote: > >> I read his slides. Great ideas but the best part is when he challenges >> Dr. Kahan with the star trek trasing/kidding. That made my day. >> Thanks for sharing Alan >> >> >> >> Inviato dal mio dispositivo Samsung >> >> >> -------- Messaggio originale -------- >> Da: Alan Wolfe <alan.wo...@gmail.com> >> Data: 14/04/2016 23:30 (GMT+01:00) >> A: A discussion list for music-related DSP <music-dsp@music.columbia.edu> >> >> Oggetto: [music-dsp] Anyone using unums? >> >> Apologies if this is a double post. I believe my last email was in >> HTML format so was likely rejected. I checked the list archives but >> they seem to have stopped updating as of last year, so posting again >> in plain text mode! >> >> I came across unums a couple weeks back, which seem to be a plausible >> replacement for floating point (pros and cons to it vs floating >> point). >> >> One interesting thing is that division is that addition, subtraction, >> multiplication and division are all single flop operations and are on >> "equal footing". >> >> To get a glimpse, to do a division, you do a 1s compliment type >> operation (flip all bits but the first 1, then add 1) and you now have >> the inverse that you can do a multiplication with. >> >> Another interesting thing is that you have different accuracy >> concerns. You basically can have knowledge that you are either on an >> exact answer, or between two exact answers. Depending on how you set >> it up, you could have the exact answers be integral multiples of some >> fraction of pi, or whatever else you want. >> >> Interesting stuff, so i was curious if anyone here on the list has >> heard of them, has used them for dsp, etc? >> >> Fast division and the lack of denormals seem pretty attractive. >> >> http://www.johngustafson.net/presentations/Multicore2016-JLG.pdf >> _______________________________________________ >> dupswapdrop: music-dsp mailing list >> music-dsp@music.columbia.edu >> https://lists.columbia.edu/mailman/listinfo/music-dsp >> >> >> >> _______________________________________________ >> dupswapdrop: music-dsp mailing list >> music-dsp@music.columbia.edu >> https://lists.columbia.edu/mailman/listinfo/music-dsp >> > >
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