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Re: Re: Re: error with Sum and Infinity

  • To: mathgroup at smc.vnet.net
  • Subject: [mg102467] Re: [mg102409] Re: [mg102387] Re: error with Sum and Infinity
  • From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
  • Date: Mon, 10 Aug 2009 04:15:40 -0400 (EDT)
  • References: <h5bk64$hlm$1@smc.vnet.net> <200908070932.FAA15211@smc.vnet.net> <29EAD82D-4D06-4036-923E-97DD7B2EDC46@mimuw.edu.pl> <4A7C6176.9060002@cs.berkeley.edu> <200908080838.EAA01301@smc.vnet.net> <op.uyfiuix8tgfoz2@bobbys-imac.local>

Yes, its undocumented. So is everything else (I think) you see when  
you evaluate

SystemOptions[]

On the other hand, SystemOptions and SetSystemOptions is documented.

I don't know if SystemOptions should be documented or not. I explained  
my reasons in an off-list discussion with a certain mythical  
scandinavian creature which from time to time visits this list, but as  
I do not feel like repeating it all here I will only say that while I  
would personally like to see more documentation I recognize that it  
would take quite a lot of time and effort to produce it and most of it  
would probably be found useful by less people than it would take to  
write it.

Andrzej


On 10 Aug 2009, at 13:31, DrMajorBob wrote:

> "SymbolicSumThreshold" is interesting... but undocumented. We cannot  
> search for it with ?, and we cannot search for it in  
> DocumentationCenter.
>
> Even now that I've seen your statement "SymbolicSumThreshold" /.  
> SystemOptions[], I have no proof it means what you suggest it means.
>
> Not that I won't take your word for it, mind you... but that's not  
> documentation.
>
> Bobby
>
> On Sat, 08 Aug 2009 03:38:55 -0500, Andrzej Kozlowski <akoz at mimuw.edu.pl 
> > wrote:
>
>>
>> On 8 Aug 2009, at 02:16, Richard Fateman wrote:
>>
>>> Andrzej Kozlowski wrote:
>>>>
>>>> On 7 Aug 2009, at 18:32, Richard Fateman wrote:
>>>>
>>>>> Well, see Elton TeKolste's remarkable post.
>>>>> I doubt that the "feature" he illustrates would be known even by
>>>>> most
>>>>> experienced users.
>>>>
>>>>
>>>> Well, you are wrong. For example, check this post (about the
>>>> fastest way of adding up a billion numbers)
>>>>
>>>> http://forums.wolfram.com/mathgroup/archive/2007/Mar/msg00565.html
>>>>
>>>> and the rest of the discussion.
>>>
>>> I think you flatter yourself and mathgroup to think that "most
>>> experienced users" will have read your post from March, 2007.
>>
>> Are you saying that there are "experienced users" who have not read
>> all my posts? Impossible!
>>
>> However, should such a strange phenomenon really exist, he or she can
>> always evaluate
>>
>> "SymbolicSumThreshold" /. SystemOptions[]
>> 1000000
>>
>> which, I think, deals with the rest of your post.
>>
>> Andrzej
>>
>>
>>
>>> I just checked the documentation and I see no notice of that magic
>>> number  (though maybe it is there somewhere and I missed it??).
>>>
>>>
>>> Is there a way of finding that magic number without experimentation
>>> or "insider" knowledge?  Would "most experienced users" know that?
>>>
>>> If it is not in the documentation, the rules of the game mean that
>>> WRI is free to change that magic number, or eliminate it, without
>>> notice, so any experienced user would be loathe to take advantage of
>>> it for fear that any program utilizing it would cease to work in a
>>> new version.
>>>
>>> RJF
>>
>>
>>
>
>
>
> -- 
> DrMajorBob at bigfoot.com



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