VOunits draft

[Hervé Wozniak]

Hi Rob,

Just a short email to clarify my purpose:

Le 27/05/2009 05:15, Rob Seaman écrivait :


>> 2.- Why do we need Zettameters? Why do we need SI prefixes?
>>
>> Is the E+22 formulation too simple and general to be acceptable?
> 
> I'm getting more confused about what is being suggested.  Are we just 
> talking about the mantissa and exponent of floating point numbers?  Or 
> is the suggestion that we have an explicit string representation for 
> scientific notation?

I just took an example to illustrate the possible lost of accuracy if 
you don't take care of the way the quantity/unit conversion is done. I 
thus showed how unit conversion is handled in some numerical simulations 
(those that are more accurate than +/-50% of course!!).
If you send "2 Gpc" to a client, it is able to keep the full accuracy. 
With 2.0E+9 pc it is less sure.

Cheers
Herve


-- 
Herve WOZNIAK

Astronome
Observatoire Astronomique de Strasbourg
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