Convergence

This is such a case when convergence is obscure, and also some result presentations that confuses (at least me).

Problem set-up for Asreml 2:
----------------------------
! Two-site, two-trait. Sites = F34
! V = vitality, H = height (standardized to s2a near 1.0)
! Tree model with pedigree, two of four sites filtered (factor, 2)
!FILTER F34 # 264 265
!DDF -1 !MAXIT 100 !CONTINUE
V_30 H_30 ~ Trait Trait.F34,
        Trait.at(F34,1).Block,
        Trait.at(F34,2).Block mv !r,
        Trait.F34.Genotype_id
2 2 1
7949 0 IDEN # 264 Vindeln
Trait 0 US 16.4 0 3.17 !GU
7864 0 IDEN # 265 Villvattnet
Trait 0 US 15.0 0 2.79 !GU

Trait.F34.Genotype_id 2
Trait.F34 0 CORGH !GP #or !GU
0.6
0.2 0
0 0.2 0.7
1 1 1 1
Genotype_id 0 AINV

When run with !GP the components and the likelihood stabilize soon and do not change, but the iterations do not stop until the iteration limit is reached. Then, the result is presented as in 1. below. In the RES file, the last column added differs from the stable values, see "Finish res" below. In the ASR file, still another component vector is presented, see "Finish ASR" below.

When run with !GU the behaviour is like expected with convergence (before getting as fixed as in the !GP case) with a slightly non-positive definite correlation matrix. The last RES column equals the ASR column. Excerpts from the RES/ASR files:

1. With CORGH !GP 2. With CORGH !GU
---------------------------------------- -----------------
Stable res Finish res % Finish asr % Finish res/asr %
---------------------------------------- -----------------
16.4689 16.4689 0 16.4689 0 16.4685 0
0.298326 0.298326 0 0.298795 0 0.309826 0
3.18372 3.18372 0 3.18374 0 3.183937 0
15.068 15.068 0 15.068 0 15.0677 0
5.569687 5.569687 0 5.57104 0 5.602113 0
4.769561 4.769561 0 4.77056 0 4.79493 0
0.916608 0.925867 1 0.925867 15 0.925305 0
0.128836 0.130137 1 0.130162 0 0.130485 0
-0.100716 -0.101733 1 -0.101709 0 -0.100732 0
0.37568 0.379475 1 0.379534 2 0.381465 0
0.351437 0.354987 1 0.355053 2 0.357152 0
0.780453 0.788337 1 0.788312 9 0.787729 0
1.027617 1.027617 0 1.02762 0 1.028345 0
1.062174 1.062174 0 1.06217 0 1.062729 0
0.986806 0.986806 0 0.986812 0 0.987396 0
1.16522 1.16522 0 1.16529 0 1.164835 0

Questions: What happened in the !GP run? Please explain! Would it be a good idea to rather use the component estimates in the "Stable res" column than any result from those ASR files?

Tore Ericsson
Skogforsk, Sweden
Received on Wed Nov 17 2009 - 12:14:52 EST