[Rd] 0.45<0.45 = TRUE (PR#10744)

[(Ted Harding)]

On 13-Feb-08 12:40:48, Barry Rowlingson wrote:
> hadley wickham wrote:
> 
>> It's more than that as though, as floating point addition is
>> no longer guaranteed to be commutative or associative, and
>> multiplication does not distribute over addition. Many concepts
>> that are clear cut in pure math become fuzzy in floating point
>> math - equality, singularity of matrices etc etc.
> 
>   I've just noticed that R doesn't calculate e^pi - pi as equal to 20:
> 
>   > exp(pi)-pi == 20
>   [1] FALSE
> 
>   See: http://www.xkcd.com/217/
> 
> Barry

Barry,
These things fluctuate. Once upon a time (sometime in 1915 will do)
you could get $[US]4.81 for £1.00 sterling.

One of the rare brief periods when the folks on opposite side
of the Atlantic saw i^i (to within .Machine$double.eps, which
at the time was about 0.001, if you were lucky and didn't
make a slip of the pen).

R still gets it approximately right:

  1/(1i^1i)
  [1] 4.810477+0i

$i^i = £1

Best wishes,
Ted.

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Date: 13-Feb-08                                       Time: 15:57:02
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