Hi everybody,
After learning R about 9 months ago, I am finally graduating from debugging by using print() statements every other line. I am now a pretty constant user of browser() and debug(). I have recently become aware of a few more tools: traceback(), trace(), and recover().
Does anybody have advice on when (and how) to use these?
The best walkthrough I've seen so far is:
http://www.biostat.jhsph.edu/%7Erpeng/docs/R-debug-tools.pdf
Anybody agree/disagree?
Mark Bravington's debugger which is available as the package debug on CRAN is very good and pretty straight forward.
library(debug);
mtrace(myfunction);
myfunction(a,b);
#... debugging, can query objects, step, skip, run, breakpoints etc..
qqq(); # quit the debugger only
mtrace.off(); # turn off debugging
The code pops up in a highlighted Tk window so you can see what's going on and, of course you can call another mtrace() while in a different function.
HTH