Typically when I am debugging an 'lapply', I put a browser call inside the lapply function that is being called and then make sure I 'source' in the code instead of copy/paste -- the copy/paste will use any trailing statements after the lapply call as commands to the "browser" function.
Here is the modified code I used: lapply( 1:3, function( x ){ browser() x + 1 } ) Here is the output from the console after "sourcing" in the statements above: > source('clipboard') Called from: FUN(1:3[[1L]], ...) Browse[1]> ls() [1] "x" Browse[1]> x [1] 1 Browse[1]> n debug at clipboard#3: x + 1 Browse[2]> x [1] 1 Browse[2]> n Called from: FUN(1:3[[2L]], ...) Browse[1]> x [1] 2 Browse[1]> n debug at clipboard#3: x + 1 Browse[2]> Called from: FUN(1:3[[3L]], ...) Browse[1]> n debug at clipboard#3: x + 1 Browse[2]> x [1] 3 Browse[2]> n > On Tue, Dec 11, 2012 at 1:17 PM, Asis Hallab <asis.hal...@gmail.com> wrote: > Dear R experts, > > recently I tried to debug a R function with an internal lapply call. > When debugging I seem not to be able to use the "n" command to debug the > inner function called by lapply. > How could I achieve this? > > *For example:* > test <- function( ) { > lapply( 1:3, function( x ) x + 1 ) > } > debug( test ) > > *Start debug:* >> test() > debugging in: test() > debug bei #1:{ > lapply(1:10, function(x) x + 1) > } > Browse[2]> n > debug bei #2:lapply(1:10, function(x) x + 1) > > *The next "n" does not allow me to inspect the inner function,* > *but gives me the result directly:* > Browse[2]> n > exiting from: test() > [[1]] > [1] 2 > > [[2]] > [1] 3 > > [[3]] > [1] 4 > > Can anyone help me, please? > Kind regards! > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@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. -- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. ______________________________________________ R-help@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.