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   screwlisp (screwtape@mastodon.sdf.org)'s status on Tuesday, 07-Jan-2025 05:16:10 JST screwlisp

   • Kent Pitman
   • Juan M. Bello-Rivas

   @kentpitman @rwxrwxrwx
   could I get you two's opinions on my conference paper idea for #ELS2025:
   https://codeberg.org/tfw/cl-series-fft#headline-4

   I eventually scrapped together a 3 element Winograd #FFT that was compatible with Waters' Series 1400 line expansion. This year's theme is "going beyond macros" and Series is kinda beyond other macros.

   I did it by hand to figure things out, but later I could cover/follow Sidney Burrus' PFA program-generation book, but for #lisp, with Series (instead of Fortran).

   • Embed this notice
     screwlisp (screwtape@mastodon.sdf.org)'s status on Tuesday, 07-Jan-2025 05:20:31 JST screwlisp

     in reply to

     • Kent Pitman
     • Juan M. Bello-Rivas

     @kentpitman @rwxrwxrwx
     otherwise, people often use bordeaux-fft, which are length two (trivial) composite ffts, or else go to C's (Burrus') fftw. I think series-optimised lisp native fft generation sounds exciting. With Series' laziness, it could even add a Goertzel's-like dimension (only evaluating targetted bins through laziness).

   • Embed this notice
     screwlisp (screwtape@mastodon.sdf.org)'s status on Tuesday, 07-Jan-2025 05:24:35 JST screwlisp

     in reply to

     • Kent Pitman
     • Juan M. Bello-Rivas
     • DougMerritt (log😅 = 💧log😄)

     @dougmerritt
     I ran out of characters to tag you but I was waiting for this <3
     As you know, Winograd's algorithm is only/especially interesting for small primes. To my knowledge one would never go past fifty, and The Usual Winograd's algorithm generations don't go above the 20s, if I recall correctly (you probably recall better).

     Anyway, there turn out to be lots of numbers that are multiples of three as well as two, in the first place. Infinitely many ;p

     @kentpitman @rwxrwxrwx

   • Embed this notice
     DougMerritt (log😅 = 💧log😄) (dougmerritt@mathstodon.xyz)'s status on Tuesday, 07-Jan-2025 05:24:36 JST DougMerritt (log😅 = 💧log😄)

     in reply to

     • Kent Pitman
     • Juan M. Bello-Rivas

     @screwtape @kentpitman @rwxrwxrwx
     Winograd had a separate FFT per prime length, composing for composite lengths. So we can expect you to also have one per prime p, right? How many primes could there be, after all.

   • Embed this notice
     screwlisp (screwtape@mastodon.sdf.org)'s status on Tuesday, 07-Jan-2025 06:27:15 JST screwlisp

     in reply to

     • Kent Pitman
     • Juan M. Bello-Rivas
     • DougMerritt (log😅 = 💧log😄)

     @dougmerritt
     Hah, yeah, but I think that the series-expanded code will let us do specific-bins calculation in a special way enabled by lisp's cl-series.

     Also, I hand-hacked this machine-generated in-place code into successfully-being-admitted-by-cl-series. So I am not arguing my code was good at all here, just that it worked at all and indicates it's possible.

     Burrus-style generated wfta I used as a reference: https://web.archive.org/web/20081220142747/http://cnx.org/content/m17626/latest/
     @kentpitman @rwxrwxrwx

   • Embed this notice
     DougMerritt (log😅 = 💧log😄) (dougmerritt@mathstodon.xyz)'s status on Tuesday, 07-Jan-2025 06:27:17 JST DougMerritt (log😅 = 💧log😄)

     in reply to

     • Kent Pitman
     • Juan M. Bello-Rivas

     @screwtape @kentpitman @rwxrwxrwx
     More seriously, I always found it intensely annoying that fftw claimed copyright/license on generated code.

     Less seriously again:

     "name idea is A Worse Is Better Way Of Computing A Fourier Transform"

     Not "Better is Worse"?

     > PROGN...PROGN...PROGN...SETQ...SETQ...SETQ...GO #....GO #...GO #...

     My mistake, worse it is. ;)

     Anyway leveraging name recognition on "Worse is Better" really is a good naming idea.

   • Embed this notice
     DougMerritt (log😅 = 💧log😄) (dougmerritt@mathstodon.xyz)'s status on Tuesday, 07-Jan-2025 06:27:18 JST DougMerritt (log😅 = 💧log😄)

     in reply to

     • Kent Pitman
     • Juan M. Bello-Rivas

     @screwtape @kentpitman @rwxrwxrwx
     > I ran out of characters to tag you but I was waiting for this <3

     It's *almost* like you're saying I'm some kind of smart ass.

     > only/especially interesting for small primes

     That's quitter talk!