Re: Random Coeffecients Model

# Re: Random Coeffecients Model

```
Dear Terry,

I havn't checked the model in detail but there is a problem with
the specification of the G structure at the bottom.

pot 2   # define 2 variance structures for Pots
48 0 I  # independence between Pots
2 0 CORR .329 82.8914 15.8124 # but corr{intercept.slope} within Pots

SHOULD BE

pot 2   # define 2 variance structures for Pots
2 0 CORR .329 82.8914 15.8124 # but corr{intercept.slope} within Pots
48 0 I  # independence between Pots

because the 96 effects to which this structure
is applied (pot and pot.vtime)

are arranged as 2 sets of 48, not 48 sets of 2.

1.  you could have used  dev(vtime)  in place of  ftime

2.  you are right that the multivariate input format
used in the random coefficients example on page 143/144
is not suitable for unequally spaced times (the more usual situation).
Note however that the G structure definition there is consistent
with what I have specified above.

Best wishes for Christmas and the new year.

Arthur

>
> Dear ASREMLers,
>
> Would someone please care to run their eye(s) over my code below ----- I am
> fitting a full model of terms, hoping to be correctly including a random
> slopes
> and intercepts model, correlated for each unit.
>
> At 18 (un-equally spaced) times, records were taken of the water usage of
> plants in 48 pots (made up of 3 reps of 4 species by 2 water regimes by 2
> fertilizer rates).  Since my time intervals are not consistent, I cannot see
> how to use the example on pages 143/144  of the Oct 1998 manual.
>
> Thanks for your time.
> Cheers,  Terry
> ========================================================
> Bill Johnston's water use data: 4 sp X 2 Water X 2 Fert
> # 18 times * 48 pots = 864 units; time 1 data (26 Sept) dropped
> #
>    species    4 !A   # Consol, 4650, Lucerne, Phalaris
>    water      2 !A   # Low, High
>    fertil     2 !A   # Low, High
>    treat     16      # Factor coding for the above 3 treatments
>    rep        3      # Factor for reps
>    pot       48      # Factor for 3rep * 4 sp * 2 water * 2 fertilizer
>    vtime        !-340.778 !/25.879   # Variate days {291...379}
>    fdate     18 !A   # Factor of 18 dates: 18-Oct, 30-Oct, .......
>    ftime     18      # Factor of 18 dates: 1,2,3,...,18
>    usage             # cumulative water usage data
> #
> d:\1_data\johnston\wateruse\BJ_treat\wuetrial.dat !skip 1 !maxit 30
> #
> # Fit a random coefficients model
> usage  ~ mu species*water*fertil ,
>    vtime vtime.spe vtime.wat vtime.fer,
>    vtime.spe.wat vtime.spe.fer vtime.wat.fer,
>    vtime.spe.wat.fer,
>    !r pot                  82.8914, # random intercepts for pots
>    pot.vtime               15.8124, # random slopes for pots
>    spl(vtime)               0.00001,
>    spe.spl(vtime)           1.5492,
>    wat.spl(vtime)          36.0471,
>    fer.spl(vtime)           0.01632,
>    spe.wat.spl(vtime)       0.07648,
>    spe.fer.spl(vtime)       0.00001,
>    wat.fer.spl(vtime)       0.009266,
>    spe.wat.fer.spl(vtime)   0.00001,
>    ftime                   17.0388,  # random lack of fit for time
>    ftime.treat              0.062343,# departures from smoothness for treats
>    pot.spl(vtime)           1.14104  # pick up curvature for each pot
>
> 0 0 1   # there is 1 G header line
> pot 2   # define 2 variance structures for Pots
> 48 0 I  # independence between Pots
> 2 0 CORR .329 82.8914 15.8124 # but corr{intercept.slope} within Pots
> ======================================================================
> *******************************************************************
> Terry Koen							EMail:
koentb@ozemail.com.au
> Research Centre						Phone: 	(02)
6342 1811 (w)
> Dept Land and Water Conservation				(02) 6341 1368
(h)
> PO Box 445, Cowra, NSW 2794,		Fax:	(02) 6342 4551
> 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

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
```