[R-sig-ME] Help! What are the typical diagnosis that one can do when, facing "fail to converge"?

[Highland Statistics Ltd]

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> Message: 1
> Date: Thu, 10 May 2012 09:35:33 -0500
> From: Michael<comtech.usa at gmail.com>
> To: r-sig-mixed-models at r-project.org
> Subject: [R-sig-ME] Help! What are the typical diagnosis that one can
> 	do when facing "fail to converge"?
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> Help! What are the typical diagnosis that one can do when facing "fail to
> converge"?
>
> Could anybody please shed some lights on us, besides increasing the number
> of iteration limit?
>
> 2012-05-10 09:28:45 :  WARNING: lme fit failed with  Error in lme(MyForm,
> data = tmp, weights = MyCovStruct, random = MyRndStruct): nlminb problem,
> convergence error code = 1
>    message = iteration limit reached without convergence (10)
>
> Thank you so much!
>
> 	[[alternative HTML version deleted]]
>
>


1. Simplify your model
2. Center or standardise your covariates
3. Increase the number of iterations
4. Lower the convergence criteria
5. Provide starting values.

Most likely you will need to do 1.
2 may work....
3-5 is for if you are stubborn and don't want to do 1.


For a more specific answer you will need to provide more details.

Alain




-- 

Dr. Alain F. Zuur
First author of:

1. Analysing Ecological Data (2007).
Zuur, AF, Ieno, EN and Smith, GM. Springer. 680 p.
URL: www.springer.com/0-387-45967-7


2. Mixed effects models and extensions in ecology with R. (2009).
Zuur, AF, Ieno, EN, Walker, N, Saveliev, AA, and Smith, GM. Springer.
http://www.springer.com/life+sci/ecology/book/978-0-387-87457-9


3. A Beginner's Guide to R (2009).
Zuur, AF, Ieno, EN, Meesters, EHWG. Springer
http://www.springer.com/statistics/computational/book/978-0-387-93836-3


4. Zero Inflated Models and Generalized Linear Mixed Models with R. (2012) Zuur, Saveliev, Ieno.
http://www.highstat.com/book4.htm

Other books: http://www.highstat.com/books.htm


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