Re: Further problem with prediction
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Further problem with prediction




> Date: Fri, 30 Oct 1998 10:04:57 +0800
> X-Sender: ngalwey@cyllene.uwa.edu.au
> Mime-Version: 1.0
> To: gilmoua@ornsun.agric.nsw.gov.au, cullisb@wagsun.agric.nsw.gov.au
> From: "N.W. Galwey" <ngalwey@cyllene.uwa.edu.au>
> Subject: Re: Further problem with prediction
> 
> Dear Arthur and Brian,
> 
>         Thank you for your full replies to my prediction query.   I'm
> clearly going to have to grapple either with .pin files, or with the
> alternative that Brian suggested.   I think there will be more queries when
> I've digested your answers, but here's just one in the meantime.   As Arthur
> surmised, the missing value were mostly to accommodate an irregular field
> lay out - COL 1 had more rows than COL 2.   Arthur, you say I should
> allocate a treatment, rep etc. to these plots.   Such allocations will be
> arbitrary: are you sure this doesn't matter?



YES
  You fit a fixed effect for each 'missing value'  so
  they do not contribute to other effects in the analysis.
  
  The purpose of allocating a treatment level though is to avoid 
  other parts of the model being confused:  Otherwise you have an extra
  'treatment group' so treatment constraints will be confounded with
  missing value effects.  You would not be sure where the singularity turned up
  and if it turned up in one of the missing values, other effects in the model
  would not be what you expected.
> 
> Best wishes,
> 
> Nick
> _____________________________________________________________________
> N.W. Galwey,
> Faculty of Agriculture,
> University of Western Australia,
> Nedlands, WA 6709, Australia.
> 
> Tel.: +61 9 380 1959 (direct line)
>       +61 9 380 2554 (switchboard)
> Fax:  +61 9 380 1108
> 


<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
Arthur Gilmour PhD                    email: Arthur.Gilmour@agric.nsw.gov.au
Senior Research Scientist (Biometrics)                 fax: <61> 2 6391 3899
NSW Agriculture                                             <61> 2 6391 3922
Orange Agricultural Institute               telephone work: <61> 2 6391 3815
Forest Rd, ORANGE, 2800, AUSTRALIA                    home: <61> 2 6362 0046

ASREML is currently free by anonymous ftp from pub/aar on ftp.res.bbsrc.ac.uk
    or point your web browser at ftp://ftp.res.bbsrc.ac.uk/pub/aar/ 

To join the asreml discussion list, send the message  
     subscribe
to  asreml-request@chiswick.anprod.CSIRO.au

The address for messages to the list is asreml@chiswick.anprod.CSIRO.au

                        <> <> <> <> <> <> <>
"Ye are not your own for ye are bought with a price: therefore glorify God
    in your body, and in your spirit, which are God's" 1 Corinthians 6:20
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>