[R] How to extract the error flag from 'try'

[Gabor Grothendieck]

On Thu, Oct 3, 2013 at 8:57 AM, Dimitri Liakhovitski
<dimitri.liakhovitski at gmail.com> wrote:
> Hello!
>
> I need to flag my operation as an error if it produces an error.
>
> For example, this expression produces an error:
> test<-try(log("a"))
> str(test)
>
> However, how can I proceed using the information contained in test object?
> I am looking for something like:
> if test is an error {do this and this}
> But I am not sure how to do it.
>
> I tried:
>
> class(test) %in% "try_error"
>

Try this code:

> res <- try(log("a"))
Error in log("a") : non-numeric argument to mathematical function
> if (inherits(res, "try-error")) cat(attr(res, "condition")$message, "\n")
non-numeric argument to mathematical function

-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com