Re: No subject given
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: No subject given



Dear Jason,
Further to our telephone discussions on Friday, for the record,

The SE of a BLUP as reported in the .sln file by ASREML is the square root
of the prediction error variance: i.e. the standard error of predicition.

Let G be the var(u), 
    P = prediction error variance = var(u-u_tilde)
    
    Var(u_tilde) = G-P     i.e. approaches G as P approaches zero
    
    Cov(u,u_tilde) is also  G-P
    
    so  'accuracy' = r =  G-P/sqrt(G*(G-P)) = sqrt((G-P)/G) = sqrt(1 - P/G)
    
         reliability = r^2 = 1 - P/G

Arthur         
         
> X-Authentication-Warning: lamb.chiswick.anprod.csiro.au: petidomo set sender 
to asreml-owner@ram.chiswick.anprod.csiro.au using -f
> From: jason.archer@smtpgwy.agric.nsw.gov.au
> Date: Thu, 10 Dec 1998 17:23:49 +1000
> To: <asreml@ram.chiswick.anprod.csiro.au>
> Subject: No subject given
> MIME-Version: 1.0
> Content-Transfer-Encoding: 7bit
> Content-Transfer-Encoding: 7bit
> Content-Transfer-Encoding: 7bit
> 
> Hi Asreml'ers
> 
> I am using ASREML to calculate BLUP EBVs for sires represented in a dataset, 
> using an animal model.
> 
> Is there a simple way (formula) to convert the Standard Errors of the 
solutions 
> in the .sln file into an accuracy as is often used when reporting EBVs  (ie. 
the
> correlation between the predicted value and the true value) ?
> 
> Thanks in advance for any help
> 
> Jason Archer
> 
> 
-------------------------------------------------------------------------------
> Dr Jason Archer                                    ph    : +61 2 6888 7404
> Livestock Research Officer (Beef cattle breeding)  fax   : +61 2 6888 7201
> NSW Agriculture                             jason.archer@agric.nsw.gov.au
> Agricultural Research Centre
> Trangie, NSW 2823, Australia     
> 
--------------------------------------------------------------------------------
> 
> 
> 
> --
> Asreml mailinglist archive: http://www.chiswick.anprod.csiro.au/lists/asreml


<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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 still 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

Asreml mailinglist archive: http://www.chiswick.anprod.csiro.au/lists/asreml

                        <> <> <> <> <> <> <>
"For the wages of sin is death,
  but the gift of God is eternal life in Christ Jesus our Lord." Romans 6:23
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>


--
Asreml mailinglist archive: http://www.chiswick.anprod.csiro.au/lists/asreml