From: luansheng <luansheng_at_GMAIL.COM>

Date: Wed, 1 Apr 2009 22:23:04 +0800

Date: Wed, 1 Apr 2009 22:23:04 +0800

Dear I.M.S.White:I think It should not be difficult. To different link

function,using different variance. It was simple programming method.

Luan sheng

----------------------------------------

Yellow Sea Fisheries Research Institute

Chinese Academy of Fisheries Sciences

Nanjing Road 106

Qingdao 266071

China

luansheng_at_gmail.com

luansheng_at_ysfri.ac.cn

----------------------------------------

2009/4/1 I.M.S.White <i.m.s.white_at_ed.ac.uk>

*> Dear Luansheng
*

*>
*

*> I agree that it is misleading. However, it might also be misleading
*

*> in some circumstances to replace the one with pi^2/3. The problem
*

*> for the programmers is devising a suitable rule for replacing
*

*> or not replacing.
*

*>
*

*>
*

*>
*

*> Quoting luansheng <luansheng_at_gmail.com>:
*

*>
*

*> Dear White: Thanks for your reply. Then my an other question is " But
*

*>> why was the variance showed as 1 other than pi^2/3 in the asr file when
*

*>> using logit link? I think it is more clear if variance was showed as
*

*>> pi^2/3.
*

*>> I have got wrong heritability because I always thought that the variance
*

*>> of logit was 1 from the asr file."
*

*>> I have sent this question to the mail list, but nobody answer me.
*

*>>
*

*>> Luan sheng
*

*>> ----------------------------------------
*

*>> Yellow Sea Fisheries Research Institute
*

*>> Chinese Academy of Fisheries Sciences
*

*>> Nanjing Road 106
*

*>> Qingdao 266071
*

*>> China
*

*>> luansheng_at_gmail.com
*

*>> luansheng_at_ysfri.ac.cn
*

*>> ----------------------------------------
*

*>>
*

*>>
*

*>>
*

*>> 2009/3/31 I.M.S.White <i.m.s.white_at_ed.ac.uk>
*

*>>
*

*>> One way the probit and logit links arise is when the event in question is
*

*>>> triggered by an unobserved variable exceeding a fixed threshold. Fixed
*

*>>> effects and variances are measured on this underlying (threshold,
*

*>>> liability) scale. If we assume the unobserved threshold variable is
*

*>>> standard
*

*>>> normal (with variance one) we get the probit link, and if we assume a
*

*>>> standard logistic
*

*>>> distribution (which has a variance of pi^2/3) we get the logit link.
*

*>>>
*

*>>>
*

*>>>
*

*>>> Quoting luansheng <luansheng_at_GMAIL.COM>:
*

*>>>
*

*>>> In the p333 of asreml 3 user guide, it is about an analysis of footrot
*

*>>> as
*

*>>>
*

*>>>> a
*

*>>>> binomial variable using the logistic link. In this example, using pi^2/3
*

*>>>> replace of error variance 1. I don't know the reason, anyone tell me?
*

*>>>> thanks!
*

*>>>>
*

*>>>> --
*

*>>>> Luan sheng
*

*>>>> ----------------------------------------
*

*>>>> Yellow Sea Fisheries Research Institute
*

*>>>> Chinese Academy of Fisheries Sciences
*

*>>>> Nanjing Road 106
*

*>>>> Qingdao 266071
*

*>>>> China
*

*>>>> luansheng_at_gmail.com
*

*>>>> luansheng_at_ysfri.ac.cn
*

*>>>> ----------------------------------------
*

*>>>>
*

*>>>> This message is intended for the addressee named and may contain
*

*>>>> confidential information. If you are not the intended recipient,
*

*>>>> please
*

*>>>> delete it and notify the sender. Views expressed in this message are
*

*>>>> those
*

*>>>> of the individual sender, and are not necessarily the views of their
*

*>>>> organisation.
*

*>>>>
*

*>>>>
*

*>>>>
*

*>>>
*

*>>> ::::::::::::::::::::::::::::::::::::::::::
*

*>>> : I.White :
*

*>>> : University of Edinburgh :
*

*>>> : Ashworth Laboratories, West Mains Road :
*

*>>> : Edinburgh EH9 3JT :
*

*>>> : Tel 0131 650 5490 Fax 0131 650 6564 :
*

*>>> ::::::::::::::::::::::::::::::::::::::::::
*

*>>>
*

*>>> --
*

*>>> The University of Edinburgh is a charitable body, registered in
*

*>>> Scotland, with registration number SC005336.
*

*>>>
*

*>>>
*

*>>> This message is intended for the addressee named and may contain
*

*>>> confidential information. If you are not the intended recipient, please
*

*>>> delete it and notify the sender. Views expressed in this message are
*

*>>> those
*

*>>> of the individual sender, and are not necessarily the views of their
*

*>>> organisation.
*

*>>>
*

*>>>
*

*>>>
*

*>>
*

*>
*

*>
*

*> ::::::::::::::::::::::::::::::::::::::::::
*

*> : I.White :
*

*> : University of Edinburgh :
*

*> : Ashworth Laboratories, West Mains Road :
*

*> : Edinburgh EH9 3JT :
*

*> : Tel 0131 650 5490 Fax 0131 650 6564 :
*

*> ::::::::::::::::::::::::::::::::::::::::::
*

*>
*

*> --
*

*> The University of Edinburgh is a charitable body, registered in
*

*> Scotland, with registration number SC005336.
*

*>
*

*>
*

*>
*

Received on Thu Apr 01 2009 - 22:23:04 EST

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