[Jprogramming] Not a Beta Problem - was Re: [Jbeta] J902 extended problem

['Mike Day' via Programming]

Thanks for trying.  I’ll clean-install j902 on my desktop,  which I don’t often use for J, and see if I can reproduce the error.  Maybe more later.

Mike

Sent from my iPad

> On 26 Oct 2020, at 23:30, Henry Rich <henryhrich at gmail.com> wrote:
> 
> I have tried to reproduce this twice: start the test, wait a while, then interrupt.  Both times the system was uncorrupted.
> 
> Can you give more info on when to interrupt to show the error?
> 
> Henry Rich
> 
> 
>> On 10/26/2020 11:24 AM, 'Michael Day' via Programming wrote:
>> PROGRESS!?
>> 
>> The problem reported under "[Jbeta] J902 exended problem" was NOT with i-beta in particular.
>> It is a bit strange,  and DOES apply to J901,  and perhaps older versions too.   Maybe
>> something to do with memory allocation for very long extended representations.
>> 
>> Something happens in the session which alters behaviour,  whereby
>> %4x is initially evaluated as 1r4,  but after an interrupt,  as shown below,  it returns
>> a value of 0.
>> 
>> I expect an easier example would give rise to the same effect, but I'll stick with the
>> latest manifestation,  which is fairly concise.
>> 
>> As I explained earlier,  and partly mis-stated,  I was exploring, in Maths-ish notation,
>> sum{k=1, n} 1 / [(b^(c^k)) . (c^k)]
>> 
>> One of my functions to explore this is
>> 
>> cumSH =: 4 : 0
>> n     =. x
>> 'b c' =. x: y
>> +/\ % b (]* ^ )  c ^ >: i.n
>> )
>> 
>> Here's a clip from a session in J 901 :
>>    %4x          NB. starts ok
>> 1r4
>> NB. cumSH soon gets slow - run too many cycles ...
>>    20 cumSH 3 10    NB. interrupted using jbreak.bat...
>> |break: cumSH
>> |   +/\%b    (]*<.@^)c<.@^>:i.n
>>    %4x              NB. different value now!
>> 0
>>    datatype%4x   NB. still extended,  though wrong
>> extended
>> 
>> JVERSION
>> 
>> Engine: j901/j64avx2/windows
>> 
>> Release-f: commercial/2020-06-11T15:31:28
>> 
>> Library: 9.01.23
>> 
>> Qt IDE: 1.8.6/5.12.7(5.12.7)
>> 
>> Platform: Win 64
>> 
>> Installer: J901 install
>> 
>> InstallPath: c:/d/j901
>> 
>> Contact: www.jsoftware.com
>> 
>> 
>> Thanks,
>> 
>> Mike
>> 
>> 
>> 
>>> On 26/10/2020 13:09, 'Michael Day' via Beta wrote:
>>> OK - home again and "solved" this difficulty with extended.  Well, chased it away -
>>> I've no idea _why_ the error arose.
>>> 
>>> So - in the absence of advice to the contrary,  I ran the prescribed update method,
>>> ie
>>>    load'pacman'
>>>    'upgrade' jpkg 'jengine'
>>> 
>>> This method had failed when I first ran it to update to beta-i , the failure manifesting
>>> itself as an error reported when starting up J902 from its Windows shortcut. That was
>>> why I had downloaded the zip file and overwritten my J902 folders with its contents.
>>> 
>>> However,  running the update in the approved manner worked today. The Windows
>>> JQt shortcut fires up the session without crashing.
>>> 
>>> Now,  I find
>>>    1%4x      NB. was 0,  yesterday !
>>> 1r4
>>>    1x%4x    NB. " " "
>>> 1r4
>>> 
>>> as expected.
>>> 
>>> Perhaps my attempt on 20/10/20 to overwrite the beta-h installation with files and folders
>>> from the zip-file went wrong somewhere...
>>> 
>>> Sorry to have raised this hare,  but it was a real anomaly yesterday!
>>> 
>>> Mike
>>> 
>> 
>> 
>> 
> 
> 
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