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  ASReml  ~  Structural vs Functional User Guides

mateus.santos
Posted: Tue Jun 19, 2018 5:29 pm Reply with quote
Joined: 31 Jul 2017 Posts: 2
Dear All,

I am a new ASReml user and will start studying how to use the software. I found two different User Guides: Structural and Funcional. Honestly, I did not find differences between them. Please, could someone tell me which of the guides I have to use and why?

Many thanks,

Mateus
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Forum Admin
Posted: Wed Jun 20, 2018 11:55 am Reply with quote
Site Admin Joined: 22 Feb 2008 Posts: 34
Dear Mateus,

If you are new to ASReml, and not trying to run legacy jobs, just focus on the Functional Guide.

ASReml was built on a former program which just allowed for identity variance structures.
So, the specification of variance structures was added on to the specification of the linear model.
This approach has been called structural because we first specified a model term
say Trait.Animal

and then specified a variance structure for it with syntax (4 four traits) like

Trait.Animal 2
Trait 0 US
10*0 # ten zeros so ASReml would generate some starting values for the US matrix
Animal 0 AIV

The specification in 2 parts was a constant source of confusion, so the Functional SYNTAX
combines the two steps by writing the model term as
us(Trait).nrm(Animal)

Either way, you need to know that you want a variance structure for the Trait.Animal term
which is a direct product of a 4x4 unstructured variance matrix and an additive relationship matrix
derived from a pedigree.

There is a new book out which you might find helpful in learning ASReml in that it is organised
more as a course, while the User Guide has a lot of information which can confuse new users.
It is

Genetic Data Analysis for Plant and Animal Breeding
by Fikret Isik James Holland Christian Maltecca
published by Springer
ISBN 978-3-319-55175-3 ISBN 978-3-319-55177-7 (eBook)
DOI 10.1007/978-3-319-55177-7
Library of Congress Control Number: 2017944107

Arthur
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mateus.santos
Posted: Wed Jun 20, 2018 7:19 pm Reply with quote
Joined: 31 Jul 2017 Posts: 2
Dear Arthur,

Thank you so much for your suggestions and explanations. I just order one book for me. It wiil help me a lot.

Best regards,

Mateus
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