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Now, now Jerkal, don't go off howling into the night... No one said you had
to use Omega's "Average" function, now did we? Matter of fact, I don't
believe the question of methods of performing functions was even raised.
The question is on precision, not function methodology...
The Okie Man
I've never been to heaven, but I've been to Oklahoma...
----- Original Message -----
From: The Jackal <tradejacker@xxxxxxxxx>
To: <omega-list@xxxxxxxxxx>
Sent: Saturday, June 19, 1999 8:18 PM
Subject: Re: Easy Language Math Precision
> selected messages from a former thread on the very same subject -- TJ
>
> oh yeah, what would be the accumulated error on 1.6 million bar with
> simple average functions in ts? now that boggles the mind even more
> than okie man's ignorance of such things!!!
>
> Resent-Date: Fri, 12 Sep 1997 06:40:00 -0700 (PDT)
> X-Sender: bfulks@xxxxxxx
> Date: Fri, 12 Sep 1997 09:29:08 -0400
> To: Scientific Approaches <sci@xxxxxxxxxx>
> From: Bob Fulks <bfulks@xxxxxxxxxxx>
> Subject: Re: EL numerical accuracy
> Cc: Omega Mailing List <omega-list@xxxxxxxxxxxxxxx>
> Resent-From: omega-list@xxxxxxxxxx
> X-Mailing-List: <omega-list@xxxxxxxxxx> archive/latest/9561
> X-Loop: omega-list@xxxxxxxxxx
> Resent-Sender: omega-list-request@xxxxxxxxxx
>
> >Massimo Ciarafoni wrote:
> >
> >> does anyone know which numerical accuracy EL does
> >> have? I mean how many decimal figures EL uses in
> >> a result, (i.e. 10/7 equals 1.42, 1.428, 1.4285,
> >> 1.42857, 1.428571 or ....). Does the price scale
> >> have any effect on the numerical accuracy?
> >
>
> Several people seemed to question the need for high accuracy in
> numerical
> calculations. Obviously, three or four digits of accuracy would
> normally be
> satisfactory for the final results. but many operations require much
> greater accuracy than this for intermediate calculations.
>
> As a very simple example, the "Average" function supplied with
> TradeStation
> calculates the average by subtracting the old bar and adding the new
> bar:
>
> Sum = Sum[1] + Price - Price[Length]
>
> This is done because it is faster than recalculating everything on each
> new
> bar.
>
> If there were even a small error on each calculation, the total error
> accumulated after hundreds or thousands of bars could be very
> significant.
> As it is, the present accuracy is barely adaquate for many operations.
>
>
> --
> Bob Fulks
> bfulks@xxxxxxxxxxx
>
> Resent-Date: Fri, 12 Sep 1997 10:40:40 -0700
> Date: Fri, 12 Sep 97 10:44:24 PDT
> From: chris@xxxxxxxx (Chris Norrie)
> To: omega-list@xxxxxxxxxx
> Subject: Re: EL numerical accuracy
> Resent-From: omega-list@xxxxxxxxxx
> X-Mailing-List: <omega-list@xxxxxxxxxx> archive/latest/9571
> X-Loop: omega-list@xxxxxxxxxx
> Resent-Sender: omega-list-request@xxxxxxxxxx
>
> Bob make a very good point in the following text. If I understand
> corectly,
> TS5 will eliminate the 13,000 bar limit, allowing systems to run on a
> much
> greater range of data. Accumulating numerical error will become an
> even
> greater problem problem unless floating point operands go to either 64
> bits
> or 80 bits.
>
> Chris Norrie
>
>
> --- Mark Brown <markbrown@xxxxxxxxxxxxx> wrote:
> I think the point is that Easy Language builds up a cumulative bunch of
> errors that anyone of by themselves is not that significant. However if
> you do big jobs and complicated systems that do require precision TS
> just can not do it. The errors will add up to the point to where you
> will be buying where you should be selling. This is the point and you
> know it weather you and PO will admit it or not. If what you say is
> true then what would your interest in Fortran be? Why what would be
> the purpose?
>
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