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Re: Evaluation question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg80361] Re: Evaluation question
  • From: David Bailey <dave at Remove_Thisdbailey.co.uk>
  • Date: Sun, 19 Aug 2007 01:29:45 -0400 (EDT)
  • References: <fa13jg$nua$1@smc.vnet.net> <fa1ckf$7qh$1@smc.vnet.net>

dimitris wrote:
> On 16    , 11:58, Yaroslav Bulatov <yarosla... at gmail.com> wrote:
>> Abs[-1 - 2 E - E ^2 + (1 + E)^2]
>> Evaluate[%]
>>
>> Why is the "N::meprec" message only printed once?
> 
> What version do you use?
> 
> In[3]:=
> Quit[]
> 
> In[1]:=
> Abs[-1 - 2 E - E ^2 + (1 + E)^2]
> Evaluate[Abs[-1 - 2 E - E ^2 + (1 + E)^2] ]
> 
>>From In[1]:=
> \!\(\*
>   RowBox[{\(N::"meprec"\), \(\(:\)\(\ \)\), "\<\"Internal precision
>       limit $MaxExtraPrecision = \\!\\(49.99999999999999`\\) reached
> while \
> evaluating \\!\\(\\(\\(-1\\)\\) - \\(\\(2\\\\ \[ExponentialE]\\)\\) -
> \
> \[ExponentialE]\\^2 + \\((1 + \[ExponentialE])\\)\\^2\\). \\!\\(\
> \*ButtonBox[\
> \\\"More...\\\", ButtonStyle->\\\"RefGuideLinkText\\\", ButtonFrame-
>> None, \
> ButtonData:>\\\"General::meprec\\\"]\\)\"\>"}]\)
> 
> Out[1]=
> Sqrt[(-1 - 2*E - E^2 + (1 + E)^2)^2]
> 
>>From In[1]:=
> \!\(\*
>   RowBox[{\(N::"meprec"\), \(\(:\)\(\ \)\), "\<\"Internal precision
>       limit $MaxExtraPrecision = \\!\\(49.99999999999999`\\) reached
> while \
> evaluating \\!\\(\\(\\(-1\\)\\) - \\(\\(2\\\\ \[ExponentialE]\\)\\) -
> \
> \[ExponentialE]\\^2 + \\((1 + \[ExponentialE])\\)\\^2\\). \\!\\(\
> \*ButtonBox[\
> \\\"More...\\\", ButtonStyle->\\\"RefGuideLinkText\\\", ButtonFrame-
>> None, \
> ButtonData:>\\\"General::meprec\\\"]\\)\"\>"}]\)
> 
> Out[2]=
> Sqrt[(-1 - 2*E - E^2 + (1 + E)^2)^2]
> 
> In[3]:=
> $Version
> 
> Out[3]=
> "5.2 for Microsoft Windows (June 20, 2005)"
> 
> Dimitris
> 
> 
> 
If you try doing exactly what Yaroslav reported, you get the same 
behaviour at 5.2. However, if you type the expression in again (or 
cut/paste it) Mathematica attacks it from scratch again, and you get a 
repeat of the diagnostic. BTW, the Evaluate wrapper does nothing in this 
context.

David Bailey
http://www.dbaileyconsultancy.co.uk


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