I am not sure why you are talking about unicode, floats and arbitrary DLLs here.
The example I showed did not involve either of those. And, especially if you are working with fixed width 1 dimensional arrays, in many cases you can use the b. derived verbs directly. It's only when you're not using array-at-a-time operations that you need concern yourself with packing/unpacking and/or padding operations, Take care, -- Raul On Tue, Aug 3, 2021 at 5:00 PM greg heil <[email protected]> wrote: > > Raul > > indeed i can make up anything > using various b. > storing seems to be reliable > only as 8b characters > i think some 16b Unicode's > are illegal > so i cannot store and manipulate > 16 bit floats that way > to do 12b floats > i might store pairs > in 3 bytes > > i suppose one could > communicate with the many > DLL's that access the > BFloat16 hiding in every AVX machine > by sifting in and out of > that format > though bytes are rather inconvenient > due to the vagaries > of how sign, multiplier and multiplicand > bits are stored > > one would prefer that that was all handled > and could check for positivity with > a simple >0 > rather than make a DLL call > or another sift > > ~greg heil > https//picsrp.github.io > > -- > > from: Raul Miller <[email protected]> > to: Programming forum <[email protected]> > date: Aug 2, 2021, 10:12 PM > subject: Re: [Jprogramming] Two implementation questions > > https://www.jsoftware.com/help/dictionary/dbdotn.htm > > #~.(i.1024) 32 b. 1 > 64 > > >Or, on my machine, the bitwise operations give me 64 bits packed in a J atom. > > >Constructing mechanisms which make an array of such things appear to be a > >bit array of arbitrary dimensions should be straightforward for someone with > >your background. (Though you could also use them "as is" with an implicit > >trailing dimension of 64.) > > Thanks, > > -- > Raul > > -- > > from: greg heil <[email protected]> > to: Programming forum <[email protected]> > date: Aug 2, 2021, 8:33 PM > subject: Re: [Jprogramming] Two implementation questions > > Henry > > Hmm, how would one create an array of bits? > use packed 8-bit characters? > would one use a similar strategy > for 16-bit floats? > (which i am more interested in, > and is directly supported in most hardware > -for its utility in Deep Learning) > > Seems a serious amount of > packing unpacking > indexing chopping and inverting > just for matrix multiplication > i could be wrong > but i do not see the algorithm > > ~greg heil > https//picsrp.github.io > > -- > > from: Henry Rich <[email protected]> > to: [email protected] > date: Aug 2, 2021, 8:07 PM > subject: Re: [Jprogramming] Two implementation questions > > >Rather than having a new datatype, you could create arrays of bits and use > >bitwise booleans on them. > > >Can you list a set of operations on bit arrays that would suffice to solve > >the problems you were working on? > > Henry Rich > > -- > > from: greg heil <[email protected]> > to: Programming forum <[email protected]> > date: Aug 2, 2021, 7:07 PM > subject: Re: [Jprogramming] Two implementation questions > > > > i did my undergraduate and doctoral thesis > on the categories of Graphs > with multiplication (and/or) as the operator > both were done using APL's bit-boolean's > > much more than just multiplication > were done on these graphs > homomorphism, isomorphism > clustering cliquing > transitive/closures > all benefited from the simpler > bit-boolean's > > as categories of graphs > run the full gamut > from 0-100% full > one cannot use > any form of linked list > > a size multiplication by 8 > would (at least in those days) > have caused a LOT of cache misses > > even now caching would > be a lot happier > because the Social Networks > under investigation > (the object of the studies) > have grown a LOT bigger!-) > > ~greg heil > https//picsrp.github.io > . > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
