Re: Spline terms
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Spline terms



Hi all,
Further to Brians comment last week:
> 
> Hi there,
> 
> I understand that if you want to fit a random spline row, you must fit a 
> fixed linear row in the model as well. So what is the difference between the 
> following two models:
> 
> Model (1)        yield ~ lin(row) genotype !r spl(lin(row))
> Model (2)        yield ~ lin(row) genotype !r spl(row)
> 
> I found in some of the wheat variety trials I analyzed, fitting Model (1) 
> caused a problem "Insufficient points for spl(lin(row))", while fitting 
> Model (2) worked well. Is this due to the lack of degree of freedom for 
> Model (1) and how is the degree of freedom estimated ? Could we just simply 
> use Model (2) in this case?

ASREML cannot interpret doubly nested terms like spl(lin(row))
at present.  The simple form   spl(row)   does the right thing - it always
uses 'row' as a variate even if it is declared as a factor (since 
a variate is always required).
> 
> Thanks for your consideration.
> 
> 
> Chungui  
> Chungui Qiao
> School of Land and Food,
> Uni of QLD
> St Lucia 4072, QLD
> Ph: (07)33652859
> Fax:(07)33651177
> 


<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>