[R] How to flag those iterations which yield a warning?

[Ravi Varadhan]

Hi,

I am running a simulation study with the survival::coxph.  Some of the simulations result in problematic fits due to flat partial likelihood. So, you get the warning message:

Warning message:
In fitter(X, Y, strats, offset, init, control, weights = weights,  ... :
  Loglik converged before variable  2 ; beta may be infinite. 

How can I keep track of the simulations which yield any kind of warning message, so that I can appropriately handle them in the post-processing of simulation results?

I know that `try' can be used to capture errors, but I would like to capture and detect warnings.

Any pointers would be appreciated.

Thanks,
Ravi.
____________________________________________________________________

Ravi Varadhan, Ph.D.
Assistant Professor,
Division of Geriatric Medicine and Gerontology
School of Medicine
Johns Hopkins University

Ph. (410) 502-2619
email: rvaradhan at jhmi.edu