[R] knitr and stopifnot replacement.

[Duncan Murdoch]

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