Re: Out of sample prediction

2000-04-03 Thread DAVE REILLY

va

   In general you should not be using regression as your problem
involves time series
http://stats.mth.uea.ac.uk/wiki/statwiki/TimeSeries.html might be of
some help in this regard.

   In particular it appears to me that that your problem is as follows


 Y   X

y1,1   0.
y2,1   0.
y3,1   0.


   yn,10.   where n is the
last observation in period 1

   y1,2   .2
   y2,2   .4
   y3,2   .45
   y4,2   .5
   y5,2   .6
   y6,2   .6

   .

   ym,2  .6




  where .2,.4,.45,.5,6,.,6..6

  reflects some assumption about growth in the second period ...leveling
off



 suggested steps

 1. Build an ARIMA model for y1,1 through yn,1
 2. Create a Transfer Function  of  Y(T)  = W(B)*X(T) + ARIMA
 3. Forecast from last observation in the first period.

This is easily done with AUTOBOX as it allows the user to pre-specify
not only the form of the model but the parameters ( in this case it is a
mixed bag empirical coefficients and form for the ARIMA component
and a user specification for the Causal component.


regards

Dave Reilly

http://www.autobox.com


P.S. If you would like we would be more than happy to demonstrate this
capability. Please call me at 215-675-0652 to discuss the details.



Victor Aina wrote:

> Hi everyone:
>
> I've got 2 non-overlapping periods. Data is
> available for period one (the first period).
> The intention is to predict observations that
> will be coming in period 2.
>
> Now, suppose an extra information is available for
> period 2. In particular, suppose it is known that
> the values of observations in the 1st half of
> period two will increase, and thereafter level off.
>
> My question is what options are available for
> capturing (in a regression model) such problem?
> And what are the caveats and/or pitfalls?
>
> Thanks for your insight.
>
> --
>
> +--+
> | victor aina  |  e-mail: [EMAIL PROTECTED] | fax:(604) 291-5944 |



===
This list is open to everyone.  Occasionally, less thoughtful
people send inappropriate messages.  Please DO NOT COMPLAIN TO
THE POSTMASTER about these messages because the postmaster has no
way of controlling them, and excessive complaints will result in
termination of the list.

For information about this list, including information about the
problem of inappropriate messages and information about how to
unsubscribe, please see the web page at
http://jse.stat.ncsu.edu/
===



Re: Exploratory data analysis

2000-04-04 Thread DAVE REILLY

 We have some material on the subject you raise.

 http://www.autobox.com/outlier.html

as it deals with exploratory data analysis ( hypothesis generation )

also

please see

http://www.autobox.com/whatis.html

If they are useful to you, please let me and the group know.

regards

Dave Reilly



Ken wrote:

> Try
>
> http://www.itl.nist.gov/div898/handbook/eda/eda.htm
>
> and here's one that will give you a headache
>
> http://seamonkey.ed.asu.edu/~behrens/asu/reports/Peirce/Logic_of_EDA.html
>
> Jostein Vada wrote:
>
> > Hi,
> > I am a norwegian PhD student within the field of process control,
> > and in 7 days I am going to defend my thesis. One part of the "exam" is
> > to give a lecture on subject which is unknown to me. Six days ago I
> > received the title:
> >
> > "Exploratory Process Data Analysis"
> >
> > Focus is on methods and theory for the data-processing stage of model
> > developement. Issues should include nonlinear filtering techniques,
> > robust statistics, redundant techniques for data analysis, data
> > reconciliation, and graphical examination of data. In other words, the
> > process from raw data until model identification.
> >
> > As far as I know, there is a huge amont of litterature on all these
> > issues. Does anyone know of  books, papers or webpages which give a
> > survey over this field?
> >
> > I'll be appreciated for any information.
> >
> > Jostein Vada



===
This list is open to everyone.  Occasionally, less thoughtful
people send inappropriate messages.  Please DO NOT COMPLAIN TO
THE POSTMASTER about these messages because the postmaster has no
way of controlling them, and excessive complaints will result in
termination of the list.

For information about this list, including information about the
problem of inappropriate messages and information about how to
unsubscribe, please see the web page at
http://jse.stat.ncsu.edu/
===