Re: VCOV structure for GxE

From: Arthur <asremlforum_at_VSNI.CO.UK>
Date: Tue, 25 Aug 2009 23:50:34 +0100

Dear Jerko

My recommendation is first
to fit env as a fixed effect

second, to omit the gen main effect when fitting a structure to the
interaction since the genetic correlation in the structure
is the gen main effect.


yield !wt weight ~ mu env !r gen.env
1 1 1
0 !S2==1.0
gen.env 2
gen 0 GIV1
env 0 CORUV .5 1.

Now your previous runs should allow a better starting value where I have 0.5 and 1

You previously have V(giv(gen)) and V(gen.env)
replace 1 with V(giv(gen)) + V(gen.env)
and 0.5 with V(giv(gen)) /(V(giv(gen)) + V(gen.env))

Once this runs, you can try CORUH, FA1, and XFA models

I trust this gets you going.

There is a longer draft exposition of these I think at
in a file called something like CHasrxfa.pdf


Arthur Gilmour

Retired Principal Research Scientist (Biometrics)

-------------------- m2f --------------------

Sent using Mail2Forum (

Read this topic online here:

-------------------- m2f --------------------
Received on Wed Aug 25 2009 - 23:50:34 EST

This webpage is part of the ASReml-l discussion list archives 2004-2010. More information on ASReml can be found at the VSN website. This discussion list is now deprecated - please use the VSN forum for discussion on ASReml. (These online archives were generated using the hypermail package.)