[R] Re: errors in randomization test

[CR Bleay, School Biological Sciences]

hello all,

last week i sent an e-mail about dealing with errors thrown up from a 
glm.nb model carried out on multiple random datasets.

every so often a dataset is created which results in the following error 
after a call to glm.nb:

"Error: NA/NaN/Inf in foreign function call (arg 1)
In addition: Warning message:
Step size truncated due to divergence"


I am at a loss as to how to deal with this.

firstly because the dataset that is generated, although throwing an error 
when the glm.nb model is applied, is a valid dataset. so how do i 
incorporate this dataset in my results (results being descriptive stats on 
the coefficients from the multiple datasets) i.e. shoould coefficients be 
set to zero?

secondly, how do i capture and deal with the error. is it possible to 
construct an "if" statement so that "if error, do this, if not continue"

lastly, i am unsure as to what characteristics of a dataset would result in 
these errors in the glm.nb?

i would be very grateful for any assistance on this matter. i having been 
staring at code for too many days now and so can't see the wood for the 
trees.


cheers,

colin
----------------------
Dr Colin Bleay
Dept. Biological Sciences,
University of Bristol,
Woodlands rd.,
Bristol,
BS8 1UG.
UK

Tel: 44 (0)117 928 7470
Fax: 44 (0)117