Every now and then I have to run a function that takes a lot of time and I need to interrupt the processing before it\'s complete. To do so, I click on the red sign of "
This could happen when R is not working within R and is invoking an external library call. The only option is to close the project window. Fortunately, unsaved changes including objects are retained on opening RStudio again.
Unfortunately, RStudio is currently not able to interrupt R in a couple situations:
R is executing an external program (e.g. you cannot interrupt system("sleep 10")
),
R is executing (for example) a C / C++ library call that doesn't provide R an opportunity to check for interrupts.
In such a case, the only option is to forcefully kill the R process -- hopefully this is something that could change in a future iteration of RStudio.
EDIT: RStudio v1.2 should now better handle interrupts in many of these contexts.