Hi, I'm running some data simulations using (mixed effects)* regression models that show difficulty to converge. Therefore, I seek a way of capturing warnings (of false convergence) inside a loop.
Inside that loop, I modify data and estimate a model. I do so many times with slightly different modifications of the data. Next, I extract some of the model parameters and store these in a matrix. However, as some of the models do not converge well, some of the stored parameters are extracted from the ill-converged models. Therefore, I seek a way of automatically detecting whether the estimation procedure has resulted in a warning, so I can distinguish between the well- and ill-converged models. I have been trying to use functions as warnings(), as well as using the object last.warning, but unfortunately to no avail. Although I cannot provide a reproducible example, I schematically represent the procedure I seek to use below: for (i in 1:10) { <<modify data>> <<estimate model>> <<<evaluate whether estimation produced warning>>> <<extract model parameters, and store whether warning occured>> } I hope any one can give some guidelines on how to deal with warnings inside a loop. With Kind regards, Rense *Although I use the lme4 package for that actual analysis, I sent my question to this mailinglist (instead of the R mixed list) because I believe this is a general issue, rather than one associated exclusively with mixed models. -- View this message in context: http://n4.nabble.com/warning-inside-loop-tp1011667p1011667.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.