Typo in my last: "gives 0.5j0" should be "Gives "_0.5j0"
Sorry. On Wed, Aug 17, 2016 at 4:43 PM, roger stokes <[email protected]> wrote: > Skip, > > you wrote "Shouldn't converting _0.25 to a SORN, then back to a > J number produce _0j0.5, NOT _0.5? " > I believe the result given is correct, because _0.25 is in the > interval (_0.5 0) in 4-bit precision. > > A =: SFJN _0.25 > > > (> A) # UNUMS > +------+ > ¦_1r2 0¦ > +------+ > > Rendering this as a complex number, with real for lower bound _1r2 > and imaginary for upper bound 0 gives 0.5j0 which is presented by J > as a real number because imag = 0 > > ] B =: JNFS A > _0.5 > datatype B > complex > B = _0.5j0 > 1 > > > I rest my case. > > These conversions are not yet finished nor documented, in fact the whole > thing is pretty rough. On that subject, let me mention that until I get it > cleaned up, users should avoid one-character lower case variables, because > of my sloppy style of doing global assigns to what should be local. > > I thought it would be best to use rationals for the values, rather than > reals, > so that the computations for the lookup tables would be exact. > > Regards > > On Wed, Aug 17, 2016 at 3:02 PM, Skip Cave <[email protected]> > wrote: > >> Playing with 4-bit unums (compact SORNS), I thought I would see how the >> J-to-SORN & SORN-to-J conversions worked: >> >> JNFS SFJN _3 >> >> __j_2 >> >> JNFS SFJN _2.5 >> >> __j_2 >> >> JNFS SFJN _2 >> >> _2 >> >> JNFS SFJN _1.5 >> >> _2j_1 >> >> JNFS SFJN _1 >> >> _1 >> >> JNFS SFJN _0.5 >> >> _1r2 >> >> JNFS SFJN _0.25 >> >> _0.5 NB. ?? >> >> JNFS SFJN _0 >> >> 0 >> >> JNFS SFJN 0 >> >> 0 >> >> JNFS SFJN 0.25 >> >> 0j0.5 >> >> JNFS SFJN 0.5 >> >> 1r2 >> >> JNFS SFJN 0.75 >> >> 0.5j1 >> >> JNFS SFJN 1 >> >> 1 >> >> JNFS SFJN 1.5 >> >> 1j2 >> >> JNFS SFJN 1.75 >> >> 1j2 >> >> JNFS SFJN 2 >> >> 2 >> >> JNFS SFJN 2.5 >> >> 2j_ >> >> JNFS SFJN 3 >> >> 2j_ >> >> JNFS SFJN _ >> >> 2j_ >> >> JNFS SFJN __ >> >> __ >> >> >> This would have been easier if JNFS and SFJN could handle vectors. In any >> case, everything looked good, once I understood how Roger was representing >> intervals in J as complex numbers, EXCEPT converting _0.25. Shouldn't >> converting _0.25 to a SORN, then back to a J number produce _0j0.5, NOT >> _0.5? >> >> >> Skip >> >> >> Skip Cave >> Cave Consulting LLC >> >> On Wed, Aug 17, 2016 at 7:21 AM, Skip Cave <[email protected]> >> wrote: >> >> > Is there a way for the unum lab to discover where it was started from, >> and >> > then set the working directory to that location, rather than having the >> > user have to set the directory? >> > >> > Skip >> > >> > Skip Cave >> > Cave Consulting LLC >> > >> > On Wed, Aug 17, 2016 at 6:47 AM, roger stokes <[email protected] >> > >> > wrote: >> > >> >> Dear All, >> >> >> >> Please accept my apologies for wasting your time, and my thanks >> >> for your patience, persistence and help. >> >> >> >> Skip, Raul, Vijay, you are quite right about 1 !: 44 . >> >> Instead of cd .... I should have said >> >> >> >> 1 !: 44 'yourdirectory' NB. full pathname is recommended >> >> >> >> >> >> Vijay, I made a correction following your mention of >> general/misc/fndef . >> >> This file should not be needed. >> >> >> >> >> >> Bob, thanks for the suggestion - it's a good way to get the lab >> started >> >> but there is still the need to find the other scripts. I will ponder >> this >> >> and see if there is a better way than as it is. >> >> >> >> Bill, thanks for the information about jconsole - I didn't know this >> >> and am very glad you mentioned it. >> >> >> >> I have now uploaded a corrected version to >> www.learningj.com/unumslab.zip >> >> . >> >> However, I hope, I believe, that the VERSION YOU ALREADY HAVE should >> run >> >> OK by doing this: >> >> >> >> 1 !: 44 'yourdirectory' >> >> >> >> first =: {. NB. workaround for Vijay's issues >> >> snd =: 1 & { >> >> >> >> load 'labs/labs' >> >> >> >> lab_jlab_ 'unums.ijt' >> >> >> >> >> >> Thanks again, everyone >> >> >> >> On Wed, Aug 17, 2016 at 4:12 AM, bill lam <[email protected]> wrote: >> >> >> >> > In the readme, it said >> >> > ... jconsole doesn't support labs >> >> > >> >> > This is incorrect. One can run labs on jconsole >> >> > and type labrun_jlab_ '' (and up arrow to recall) >> >> > to advance. >> >> > >> >> > Вт, 16 авг 2016, roger stokes написал(а): >> >> > > Dear All, >> >> > > >> >> > > I've heard it said that you don't understand a subject >> >> > > unless you can explain it to a computer. With that in mind >> >> > > I've attempted a software implementation of Gustafson's Unums 2.0 >> >> > > >> >> > > ( http://www.johngustafson.net/presentations/Unums2.0.pdf ). >> >> > > >> >> > > If anyone is interested, there is a demo available in the >> >> > > form of a J lab. To run the lab >> >> > > >> >> > > Download www.learningj.com/unumslab.zip >> >> > > >> >> > > Unzip into any convenient directory >> >> > > >> >> > > Follow directions in the readme file >> >> > > >> >> > > Comments and criticisms appreciated. >> >> > > >> >> > > Regards >> >> > > ------------------------------------------------------------ >> >> ---------- >> >> > > For information about J forums see http://www.jsoftware.com/forum >> >> s.htm >> >> > >> >> > -- >> >> > regards, >> >> > ==================================================== >> >> > GPG key 1024D/4434BAB3 2008-08-24 >> >> > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 >> >> > gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3 >> >> > ------------------------------------------------------------ >> ---------- >> >> > For information about J forums see http://www.jsoftware.com/forum >> s.htm >> >> > >> >> ---------------------------------------------------------------------- >> >> For information about J forums see http://www.jsoftware.com/forums.htm >> >> >> > >> > >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
