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Re: Numerical accuracy/precision - this is a bug or a feature?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg120315] Re: Numerical accuracy/precision - this is a bug or a feature?
  • From: Bill Rowe <readnews at sbcglobal.net>
  • Date: Mon, 18 Jul 2011 06:15:11 -0400 (EDT)

On 7/17/11 at 6:02 AM, slawek at host.pl (slawek) wrote:

>U==BFytkownik "Bill Rowe" <readnews at sbcglobal.net> napisa==B3 w
>wiadomo==B6c== i grup dyskusyjnych:ivrmkn$866$1 at smc.vnet.net...

>>SameQ requires exact correspondence between expressions, except
>>that it still considers Real numbers equal if they differ in their
>>last binary digit.

>What for 1-digit numbers? 0 == 1 ?

The example you show here has no relevance to the portion of the
documentation for SameQ I copied since you use Equal and exact
numbers. But if you were to replace the 1 with something that
approximates a real with one binary digit and the 0 with a
machine precision value, that is

In[6]:= 1.`0 === 0.

Out[6]= True

which seems consistent with the documentation.


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