>>>> https//picsrp.github.io
>>>>
>>>> --
>>>>
>>>> from: Raul Miller
>>>> to: Programming forum
>>>> date: Aug 2, 2021, 10:12 PM
>>>> subject: Re: [Jprogramming] Two implementation questions
>>
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
> >
> >
d 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
> to: Programming forum
> date: Aug 2, 2021, 10:12 PM
> subject: Re: [Jprogramming] Two imp
simple >0
rather than make a DLL call
or another sift
~greg heil
https//picsrp.github.io
--
from: Raul Miller
to: Programming forum
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.
ix multiplication
> i could be wrong
> but i do not see the algorithm
>
> ~greg heil
> https//picsrp.github.io
>
> --
>
> from: Henry Rich
> reply-to: programm...@jsoftware.com
> to: programm...@jsoftware.com
> date: Aug 2, 2021, 8:07 PM
> subject: Re: [Jprog
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 the
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
I wrote maybe 50k lines of code over two years for Dyalog 18.0. Yes,
there are bugs. There were plenty of bugs when I joined too. Frankly I
think Dyalog's response to 18.0 says as much about its relationship with
clients as about the nature of the release.
Marshall
On Mon, Aug 02, 2021 at 05:30:4
On Mon, 2 Aug 2021, Henry Rich wrote:
1a. What's an example that is greatly sped up by bitarrays?
Logical boolean ops (and/or/xor).
Perhaps more importantly, lower cache usage improves overall program
locality. (Though this becomes doubly false every time you have to
promote a bitarray to a
The recent work on bit arrays in Dyalog APL is the source of numerous
serious and subtle bugs. I am not speaking on any official capacity.
On Mon, Aug 2, 2021 at 2:56 PM Marshall Lochbaum
wrote:
> Is (64-bit) J still using 8 bytes for all its non-boolean integers and
> floats? If so I think t
Is (64-bit) J still using 8 bytes for all its non-boolean integers and
floats? If so I think that mostly explains the difference. You can't
gain that much performance by turning 8 bits to 1 when you're still
regularly dealing with 64-bit values. The biggest advantage for bit
arrays in Dyalog was us
Thank you Eric, that makes a lot of sense.
On Mon, 2 Aug 2021, Eric Iverson wrote:
bit data type:
It is partly an issue of resources and how to spend them. Adding a bit data
type is a large amount of work. And at least so far we have found better
areas to work on. Also the playing field for tho
1a. What's an example that is greatly sped up by bitarrays?
1b. J uses bitarrays internally in dyad i. when the arguments are large
and integral.
1c. I haven't seen enough advantage to suggest that bitarrays are worth
implementing. (x # y), perhaps the most important case, is dominated by
t
bit data type:
It is partly an issue of resources and how to spend them. Adding a bit data
type is a large amount of work. And at least so far we have found better
areas to work on. Also the playing field for those old arguments have
changed and continue to change. APL already has them and it shoul
J has bit arrays, though it's true that they could be a factor of 8
more space efficient by removing padding and making the J
implementation somewhat bulkier.
But you can pad your arrays yourself if you want to test whether row
alignment introduces timing advantages for frequent operations. It
wou
Apologies if this is the wrong place for this.
First: what's the deal with bitarrays? I have heard APL implementors
state with great conviction that they are worthwhile and have led to great
performance increases; and I have heard J implementors state with equal
conviction that they are not w
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