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> -----Message d'origine-----
> De : J. Rodney Grisham [mailto:Rod.Grisham@xxxxxxxxxxxxxxxxxxxxx]
> Envoye : dimanche 29 juillet 2001 00:04
> A : Bob Fulks
> Cc : omega-list@xxxxxxxxxx
> Objet : Re: TradeStation Precision - Summary
>
>
>
> Today Bob Fulks wrote (in part):
>
> > Interesting, but very fuzzy logic (pun untended, considering the
> > source). I have no more time to waste arguing with you on this.
> >
> > YOU ARE WRONG!
>
>
> In between Pierre Orphelin wrote (in part with typo's corrected):
Thanks, I can write french if you prefer.
This does not cost any effort to write in your native language, but this is
not the case for me.
>
> > Most of you forget what is the precision carried by the original data
> > (price) and what is the precison expected from any calculation that
> > derives from the original prices.
>
>
> I stayed out of this because like Bob, I have no time to waste
> arguing with PO and a few of his occasional cohorts about this
> or any other topic. We have been through this precision topic
> many times in the past.
>
> To answer Bob's first question, I don't see any errors in what
> he wrote on Thursday. I agree that PO is wrong and/or misleading.
>
> The part of PO's message which is quoted above is correct.
> One should not expect more accuracy in a computed answer than
> exists in the data provided to define the problem. But you do
> have a right to expect as much, or to be able to define how bad
> it can be (worst case).
And as this is the only remark that I was doing over and over, you cannot
say that I am wrong to please Bob and that the above quoted is correct!
Now, if your idea is to have more precision to do other things than
performing price calculation, this is beyond the scope of TS, that is not a
modelisation tool, but a technical analysis tool, based on price data.
There are plenty of software for that purpose ( Matlab, Mathcad and so on).
TS has never been designed for that,or some of you have made a casting error
whaen buying it.
>
> With 32 bit floating point precision calculations, it is VERY easy
> to get totally meaningless answers. I've spent most of my career
> solving fluid flow problems. I assure you, engineers don't have
> the instrumentation to provide problem definition to 7 decimal
> digits of accuracy, but you would not dream of trying to model
> the behavior with single precision computations.
Modeling is different than interpreting experimental results from raw
numbers.
Modeling with computers is the same than doing maths,and may require the
best precision available, because the data are generated by formulae and
theoretical calculus applied to.
This is not what we do with technical analysis when inputs data are prices
and no modeling is applied ( indicators are not modeling at all, it's only a
transform of the raw price data)
Bad trap, Rodney, and you are missing the point.
As we use to say in french,
"Vous essayez de nous faire prendre des vessies pour des lanternes"
(Typo free guaranteed for this line)
Sincerely,
Pierre Orphelin
www.sirtrade.com
TradeStation Technologies representative in France
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