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From: roberson@ibd.nrc-cnrc.gc.ca (Walter Roberson)
Newsgroups: comp.soft-sys.matlab
Subject: Re: Computer precision?
Date: Mon, 5 May 2008 16:59:00 +0000 (UTC)
Organization: National Research Council Canada - Conseil national de rechereches Canada
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In article <muyskwwj3y6.fsf@G99-Boettcher.llan.ll.mit.edu>,
Peter Boettcher  <boettcher@ll.mit.edu> wrote:
>onofftopic@gmail.com writes:

>> according to the Matlab Help double computer precision (64-bit) is
>> default in Matlab for 32-bit computers. Maybe is this question
>> offtopic, but i would like to know why is there no higher precision,
>> e.g. 128-bit precision, for 32-bit computers?

>Modern computer hardware implements 64-bit floating point very
>efficiently.  Anything larger than that requires software
>implementation.

most x86 systems have 80 bit floating point internally (though the
values are usually rounded to 64 bits when stored to memory.)

I do not know if it is possible to turn on 80 bit mode in Matlab.
I have never been able to keep track of the system dependant
functions such as system_dependant(). I didn't see anything likely
when googling, but I didn't spend particularily long at it.l

-- 
  "Is there any thing whereof it may be said, See, this is new? It hath
  been already of old time, which was before us."    -- Ecclesiastes