I don't understand what is "J would warn you". Either a J sentence executed
successfully or it raise an error exception. There is nothing in between.
What is your expected result for the case you quoted?

On Oct 8, 2017 8:34 AM, "'Skip Cave' via Beta" <[email protected]> wrote:

​​
Those examples weren't very good. Here's a better example of "blithely
returning an egregiously wrong answer".

    13 | */ 13 | 10 # 19 29 59 79 89 109 119 139 149 179 199
0

That answer is not correct. Here's the correct answer:

       13 | */ 13 | 10 # 19 29 59 79 89 109 119 139 149 179 199x

9

It would be nice if J would warn you when you get underflow or overflow in
the middle of a computation. Perhaps by inserting infinity, NaN. or some
other mechanism in that faulty result. The marker would need to propagate
unmodified through subsequent computations. Then if that marker showed up
in the final result, I would know that something got out of bounds during
the computation.

Skip

Skip


Skip Cave
Cave Consulting LLC

On Sat, Oct 7, 2017 at 6:38 PM, Henry Rich <[email protected]> wrote:

> They all look ok to me.
>
> Henry Rich
>
> On Oct 7, 2017 19:25, "'Skip Cave' via Beta" <[email protected]> wrote:
>
> > It would be marvelous if J was polite enough to warn me when a result is
> in
> > all likelihood not correct, rather than blithely returning an
egregiously
> > wrong answer.
> >
> > Skip
> >
> > <<<>>>
> >
> >     x:1.9 % 2^1024
> >
> > 0
> >
> >     1.9 %&x: 2^1024
> >
> > 0
> >
> >     1.9 % 2^1024x
> >
> > |domain error
> >
> > | 1.9 %2^1024
> >
> >
> >     1.9 %&x: 2^1024x
> >
> > 19r179769313486231590772930519078902473361797697894230657273
> > 430081157732675805500963132708477322407536021120113879871393
> > 357658789768814416622492847430639474124377767893424865485276
> > 302219601246094119453082952085005768838150682342462881473913
> > 1105408272371633...
> >
> >
> > Skip Cave
> > Cave Consulting LLC
> >
> > On Sat, Oct 7, 2017 at 12:24 PM, Skip Cave <[email protected]>
> > wrote:
> >
> > >    1.9 %&x: 2^1024x
> > >
> > > 19r179769313486231590772930519078902473361797697894230657273
> > > 430081157732675805500963132708477322407536021120113879871393
> > > 357658789768814416622492847430639474124377767893424865485276
> > > 302219601246094119453082952085005768838150682342462881473913
> > > 1105408272371633...
> > >
> > > x:1.9 % 2^1024
> > >
> > > 0
> > >
> > > 1.9 %&x: 2^1024
> > >
> > > 0
> > >
> > > 1.9 % 2^1024x
> > >
> > > |domain error
> > >
> > > | 1.9 %2^1024
> > >
> > >
> > > Engine: j805/j64/windows
> > >
> > > Release: commerciai/2016-12-11T08:02:16
> > >
> > > Library: 8.05.14
> > >
> > > Qt IDE: 1.5.4/5.6.2
> > >
> > > Platform: Win 64
> > >
> > > Installer: J805 install
> > >
> > > lnstaiiPath: c:/program files/j64 -805
> > >
> > >
> > >
> > > Skip Cave
> > > Cave Consulting LLC
> > >
> > > On Sat, Oct 7, 2017 at 10:57 AM, Skip Cave <[email protected]>
> > > wrote:
> > >
> > >> Doesn't happen on my system:
> > >>
> > >>    1.9 %&x: 2^1024x
> > >>
> > >> 19r179769313486231590772930519078902473361797697894230657273
> > >> 430081157732675805500963132708477322407536021120113879871393
> > >> 357658789768814416622492847430639474124377767893424865485276
> > >> 302219601246094119453082952085005768838150682342462881473913
> > >> 1105408272371633...
> > >>
> > >>
> > >> Engine: j805/j64/windows
> > >>
> > >> Release: commerciai/2016-12-11T08:02:16
> > >>
> > >> Library: 8.05.14
> > >>
> > >> Qt IDE: 1.5.4/5.6.2
> > >>
> > >> Platform: Win 64
> > >>
> > >> Installer: J805 install
> > >>
> > >> lnstaiiPath: c:/program files/j64 -805
> > >>
> > >>
> > >>
> > >> Skip Cave
> > >> Cave Consulting LLC
> > >>
> > >> On Sat, Oct 7, 2017 at 10:05 AM, 'Pascal Jasmin' via Beta <
> > >> [email protected]> wrote:
> > >>
> > >>>
> > >>>
> > >>> this happens in 805 too,
> > >>>
> > >>> 1.9 %&x: 2^1024x
> > >>>
> > >>>
> > >>>
> > >>> ________________________________
> > >>> From: Raul Miller <[email protected]>
> > >>> To: Beta forum <[email protected]>
> > >>> Sent: Saturday, October 7, 2017 8:56 AM
> > >>> Subject: [Jbeta] Do I need to upgrade?
> > >>>
> > >>>
> > >>>
> > >>> I was expecting a zero or a small value from this expression -
> > >>>
> > >>> instead, I got an error.
> > >>>
> > >>>
> > >>>    1.9%2^1024x
> > >>>
> > >>> |domain error
> > >>>
> > >>>    JVERSION
> > >>>
> > >>> Engine: j806/j64/darwin
> > >>>
> > >>> Beta-6: commercial/2017-09-26T14:12:52
> > >>>
> > >>> Library: 8.06.07
> > >>>
> > >>> Qt IDE: 1.6.1/5.6.3
> > >>>
> > >>> Platform: Darwin 64
> > >>>
> > >>> Installer: J806 install
> > >>>
> > >>> InstallPath: /users/rauldmiller/applications/j64-806
> > >>>
> > >>> Contact: www.jsoftware.com
> > >>>
> > >>>
> > >>> (I was trying to investigate the representation of denormalized
> > numbers.)
> > >>>
> > >>>
> > >>> Thanks,
> > >>>
> > >>>
> > >>> --
> > >>>
> > >>> Raul
> > >>>
> > >>> ------------------------------------------------------------
> ----------
> > >>>
> > >>> 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
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
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For information about J forums see http://www.jsoftware.com/forums.htm
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