Actually, ... the numbers I was seeing suggested somewhat over 36GB
would be used. But the OS needs some memory also, and there wasn't any
benefit that I could see in being overly accurate, so I rounded that
to "about 40GB"

FYI,

-- 
Raul

On Sun, Feb 7, 2021 at 3:04 PM 'Michael Day' via General
<[email protected]> wrote:
>
> I don't think your problem was the spec of your pc,  although 8GB is
> pretty good.
>
> Mine, with 16GB RAM,  got stuck with taking all triples, seeming to need
> ~38GB,
> and Raul's analysis also suggests 40GB .
>
> Cheers,
>
> Mike
>
> On 07/02/2021 17:05, Francesco Pedulla' wrote:
> > Thanks to all that answered so quickly. In particular:
> > @Brian: yes, I was aware that a smaller case would work
> > @R.E.: your suggestion to skip the boxing seems to avoid the issue
> > altogether (see working code below)
> > @Michael: congrats for reading my code so well - in fact, I messed it up
> > while producing a slimmed down version to share; w.r.t. boxing, see my
> > answer to R.E.
> >
> > Now the fixed code reads
> >
> >
> > perm =: i.@! A. i.
> >
> > base10 =: 10&base
> >
> > PanDigS =: (perm 10) from i.10
> >
> > PanDigT =: 3 base10\"1 PanDigS
> >
> >
> > It does not break anymore (logical correctness is another story).
> >
> >
> > The fact that the new code completes without errors suggests that the issue
> > lies with the boxing operation. It could be either directly or indirectly,
> > e.g. by stressing the operating system memory management code (paging?).
> > Should someone investigate, I add that my machine is an old HP 280 with a
> > dual core Celeron CPU [email protected] and 8GB of RAM.
> >
> >
> > Best regards,
> >
> >
> > Francesco
> >
> > ---------- Forwarded message ---------
> > From: Francesco Pedulla' <[email protected]>
> > Date: Sun, Feb 7, 2021 at 12:32 PM
> > Subject: Bug in J807/J902
> > To: <[email protected]>
> >
> >
> > The following piece of code does not work on Ubuntu 20.04.
> >
> > load 'primitives'
> >
> > perm =: i.@! A. i.
> >
> > PanDigS =: (perm 10) from (1 + i.10)
> >
> > PanDigT =: 10 base"1 each 3 box\"1 PanDigS
> >
> >
> > The effect is variable: crash of the J interpreter, freeze of the Qt
> > interface or even of the whole system. It shows up both on J807 and J902.
> >
> > The dataset is quite large:
> >
> >
> > 7!:5 <'PanDigS'
> >
> > 5.36871e8
> >
> >
> > and the process crashes (or the system freezes) after several seconds.
> > Hence, I suspect an issue with memory management.
> >
> > Any idea or suggestion on how to bypass the problem?
> >
> > Thanks,
> >
> >
> > Francesco
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
>
> --
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