R help - Aug 2014 - knitr and stopifnot replacement.

I have a daily generated report in which I put a check using stopifnot. 
Unfortunately
I didn?t check the effect very well, turns out that if the condition checked
fails
this is not shown in the knitr output (I only get an error much later due to a
missing
object).

So my question is, what is the correct way to use assertions in a
<filename>.Rnw
file.  I want to perform a check, and if it fails everything should stop with a
message
I can generate.

Thanks,

Best,
Bart

On 22/08/2014, 6:02 AM, Bart Kastermans wrote:
> I have a daily generated report in which I put a check using stopifnot. 
Unfortunately
> I didn?t check the effect very well, turns out that if the condition
checked fails
> this is not shown in the knitr output (I only get an error much later due
to a missing
> object).
> 
> So my question is, what is the correct way to use assertions in a
<filename>.Rnw
> file.  I want to perform a check, and if it fails everything should stop
with a message
> I can generate.
> 
One of the differences between knitr and Sweave is that knitr handles
errors, and Sweave doesn't.  I expect there's some knitr option to tell
it to quit in case of error (a hook?), but you'll have to check the
documentation to find it.

Duncan Murdoch