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Subject: Re: even and odd numbers
Date: Thu, 29 Jan 2009 03:53:01 +0000 (UTC)
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"us " <us@neurol.unizh.ch> wrote in message <glp6mp$kq1$1@fred.mathworks.com>...
> .......
> % BITMAX is the largest number, which gives a correct result...
>      help bitmax
> .......

  I agree with you, Urs.  'bitmax' would be the largest number that would give the correct answer as to a double floating point integer's least bit.

  However, it is rather amusing to read Mathworks' documentation for 'bitmax'.  They say, "bitmax returns the maximum unsigned double-precision floating-point integer for your computer. It is the value when all bits are set, namely the value 2^53-1."  This is wildly wrong!  In fact every floating point number beyond that is of necessity an integer and what is more, an even integer.  They meant to say something very different - something like: beyond this all numbers must have a zero in their units binary digit position and therefore can represent neither numbers with a fractional part nor odd integers.

Roger Stafford