RE: [GT] ADX

["Weigert, Thomas" <weigert AT mst.edu>]

Please see below....

> -----Original Message-----
> From: Robert A. Schmied [mailto:ras
AT
acm.org]
> Sent: Monday, March 03, 2008 6:08 PM
> To: devel
AT
geniustrader.org
> Subject: Re: [GT] ADX
> 
> tangent on
> and gee they (wilder and wwma) don't generate the same results -- but
> that's not too surprising.

The difference is that WWMA starts with 0 but Wilders starts with the
n-day SMA (as stated in Wilders article).


> 
> is there a (mathematical) way to determine if one is wrong? or are we
> subject
> to ta-lib says this, Metastock that ...

Most of the time, the papers or articles these indicators are based on
are not very clear on details, e.g., what starting value to use, what
smoothing functions to use, etc. So implementers often have to make
these decisions based on their intuitions. Also, there really is no
right or wrong here... there is no mathematical reason why one should
use EMA vs. SMA vs. any of the many other smoothing operations.

> crap -- i'm not too partial to 'dies' in the middle of a program;
> this one is of the particularly annoying type. but (there's always a
but)
> i like the fact that the indicator makes the effort to check it's args
and
> report problems. however, when triggered, you get a perfectly
accurate,
> but
> relatively unhelpful message:
> 'Argument 1 must be a constant value.'
> 
> the following info added to the error message would be a big help:
> @ the module (indicator) that is complaining
> @ the Argument that is being complained about

That is a good suggestions. I am planning to add a generic function to
indicators that would allow some error checking to be done
automatically.


Th.