Arthur(et al),
Thanks for the free publicity earlier in the week. I certainly found
your response most helpful, so I hope some others found it useful also.
I have two further matters. The first is rather trivial but confirmation
of my observation would be appreciated. I have some data which has
missing values for the response variate yield ( indicated by *'s ). When
I read it into ASREML it indicates the #miss is zero. More careful
inspection indicates the # of records retained = total observations -
#missing etc and it appears that the *ing values have been recognised
appropriately, as stated in the manual. Is this in fact correct and there
is a minor bug in #miss shown??
My second ? is less trivial (I think). I have data where I expect a model
with common intercept but different slope would seem likely given the
biology. That is, at time zero it would be expected all treatments start
at the same value and gradually separate depending on the treatments.
Thus I fit
yield ~ mu variate #for a common line
then yield ~ mu variate factor.variate #common intercept different
slope. This second model appears strange and in fact bears little
similarity to REML (in GENSTAT). Whereas the model
yield ~ mu variate factor factor.variate #different intercept and
slope,
and the initial model appear reasonable and are consistent with REML.
Is there any reason why this second model should "upset" ASREML ??
Note eventually I want to fit a much more complicated model involving
pol(), spl() and other factors but if the simple 2nd model doesn't give
me what I expect I'm a little reluctant to head for the "deep water" and
beyond, without some advice from the lifeguard(s).
Cheers, Trevor.
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TREVOR W HANCOCK, Biometry, Dept. of Plant Science, Univ. of Adelaide.
Waite Institute, PMB 1 Glen Osmond, South Aust.,AUSTRALIA. 5064
Tel: (08) 8303 7288 International: 61 8 8303 7288
Fax: (08) 8303 7109 International: 61 8 8303 7109
email: thancock@waite.adelaide.edu.au
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