[R] nls error control

[Timothy R. Johnson]

I'm running a simulation that uses nls on each run. Sometimes, not
unexpectedly, nls doesn't return parameter estimates (e.g., "singular
gradient" error). Of course when this happens the simulation (in a loop)
stops and no results are recorded. What I would like is for the simulation
to simply record that nls couldn't obtain estimates on a particular run due
to whatever difficulties it encountered but to not return an error that
stops the entire simulation.

Has anyone worked-out a tweak to do this? I'm using version 1.4.1 under
Linux.

Best regards,

Tim Johnson

---------------------------------
Assistant Professor of Statistics
University of Idaho
Moscow, Idaho 83844-1104
trjohns at uidaho.edu
http://www.uidaho.edu/~trjohns


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