[R-meta] Inquiry on metafor trimfill and weightr

[Michael Dewey]

Dear Chishio

Do the two methods stop on the same data sets? As well as possibly 
giving you a clue as to what is happening that would, in my opinion, 
make leaving those sets out more justifiable for your comparison.

Michael

On 19/12/2018 12:50, Chishio Furukawa wrote:
> Dear the community of metafor users,
> 
> I am writing to seek your advice for using the metafor trimfill (Duval and
> Tweedie 2000) and weightr (Hedges and Vevea 2005).
> 
> Currently I am conducting a simulation study comparing their performance
> across various models of publication selection. However, when I looped over
> many simulated meta-analysis data sets, I encountered various errors that
> stopped the loop. I am writing to ask your advice on what I can do to
> address them.
> 
> 1) trimfill
> - for some data, I receive an error message "Trim and fill algorithm did
> not converge."
> 2) weightr
> - for some data, there is an error with "optim" package that has
> "non-finite finite-difference value."
> - the Hessian is non-singular so I cannot calculate the standard error of
> each parameter.
> 
> May I ask if anyone could advise me on (i) what features of data create any
> of these problems, and (ii) if there are ways to let the computation go
> through without having the code break? I am thinking, after all, I could
> skip these few simulation data sets that generate the prolems, and compute
> the coverage probabilities and interval lengths on the data that do not
> have these problems (although that might not be the most ideal way to
> address them.)
> 
> Thank you so much in advance for your advice.
> 
> Best regards,
> Chishio
> 
> 
> 
> 

-- 
Michael
http://www.dewey.myzen.co.uk/home.html