R help - Dec 2011 - help! what's wrong with setBreakpoint

Hi all,

I am in the middle of debugging which is stopped using "browser()"...
in
myfile.R at around line #25.

I was then stuck in a big loop which I want to escape and stop the program
at the line after the big loop.

In the debugging mode, I used

   Browse[2]> setBreakpoint("myfile.R#38")

I then typed "c" and "ENTER", thinking that it will continue
to execute
until when it comes across line #38 and then stop there...

But it didn't work - it continued the execution until the end of the
function, right at the line "return(results)"...

What happened? How to solve this problem?

Thanks a lot!

	[[alternative HTML version deleted]]

A function is a parsed object stored in memory; your edit applies to the source,
but not to the memory object being executed. There is no way, to my knowledge,
to use browser to alter the execution flow of an function once it's going
(other than changing values of course). You need to edit the function definition
to put the breakpoint where desired and then reread and rerun the function.

Michael

On Dec 5, 2011, at 10:32 PM, Michael <comtech.usa at gmail.com> wrote:
> Hi all,
> 
> I am in the middle of debugging which is stopped using
"browser()"... in
> myfile.R at around line #25.
> 
> I was then stuck in a big loop which I want to escape and stop the program
> at the line after the big loop.
> 
> In the debugging mode, I used
> 
>   Browse[2]> setBreakpoint("myfile.R#38")
> 
> I then typed "c" and "ENTER", thinking that it will
continue to execute
> until when it comes across line #38 and then stop there...
> 
> But it didn't work - it continued the execution until the end of the
> function, right at the line "return(results)"...
> 
> What happened? How to solve this problem?
> 
> Thanks a lot!
> 
>    [[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

On 11-12-05 10:32 PM, Michael wrote:
> Hi all,
>
> I am in the middle of debugging which is stopped using
"browser()"... in
> myfile.R at around line #25.
>
> I was then stuck in a big loop which I want to escape and stop the program
> at the line after the big loop.
>
> In the debugging mode, I used
>
>     Browse[2]>  setBreakpoint("myfile.R#38")
What did it print?
>
> I then typed "c" and "ENTER", thinking that it will
continue to execute
> until when it comes across line #38 and then stop there...
>
> But it didn't work - it continued the execution until the end of the
> function, right at the line "return(results)"...
>
> What happened? How to solve this problem?
One of the complications in R is that you can have multiple copies of a 
function in memory.  You may (or may not, what did it print??) have set 
a breakpoint in one copy, then run another.  Or you may have edited that 
function after originally sourcing it, and lost the source reference.

An alternative to using setBreakpoint is just to edit a call to 
browser() into the function.  It's less convenient, but more robust.

Duncan Murdoch
> Thanks a lot!
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.