[R] how to ignore error messages?

[Dieter Menne]

Jianping Jin <jjin <at> email.unc.edu> writes:
...
> I wrote a code to iterate a non-linear fit with a set of data. The entire 
> process didn't implemented to the end because an error message, "singular 
> gradient". I knew that some sub-sets (columns) do not fit my formula well 
> and may result in parameters going to infinity. It is pretty hard to remove 
> those sub sets before running the code since that will take a lot of time.
> 
> I added some logic assessments prior to running nonlinear fit. It helped 
> but some exceptions still existed. I am wondering if there is any way in R 
> by which I can continue to run the entire code to the end by ignoring the 
> error message?
...

?try

Or, even easier, use nlsList in nlme, which does exactly what you want, handling
convergence errors graciously.

Dieter