[R] how to trap any warnings from an R function

[Boryeu Mao]

Thanks for the reply.  The problem that I have in a nutshell is the
following:

usertest <- function {
 ...
 reg<-polr(act~., data=mm)
 summary(reg)
 return(reg$AIC)
 }

For some data, NaN's are produced (in sqrt(diag(vc))), and I'd like to trap
this condition and any other warnings, so that a negative value, say, can be
returned to the calling function to indicate the warning condition.
Warnings from 
summary() are produced and placed in 'last.warning' but that is accessible
only at the top-level, not within usertest(); I've tried setting 'warn' in
options() but hadn't found a way to do this.  I'm still searching various
docs for any ideas, and it seems to be something that might be quite
straightforward.  Any points/ideas are appreciated.   Thanks!


-----Original Message-----
From: Jason Turner [mailto:jasont at indigoindustrial.co.nz]
Sent: Tuesday, April 30, 2002 12:23 PM
To: Boryeu Mao
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] how to trap any warnings from an R function


On Mon, Apr 29, 2002 at 12:43:56PM -0700, Boryeu Mao wrote:
> Within an user function, how are the warnings from an R function be
trapped
> (such that some proper actions can be taken)?  

One way is with try()

Cheers

Jason
-- 
Indigo Industrial Controls Ltd.
64-21-343-545
jasont at indigoindustrial.co.nz
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