How about 'traceback'? (It does not necesssarily show all the frames, but it does help and the exceptions are fairly esoteric.)
On Mon, 28 May 2007, ronggui wrote: > In that "the meaning of parent.frame depends on where it is > evaluated", is there a nice way to figure out which frame an express > is evaluated? for example, I would like to konw what does > parent.frame(2) refer to. > >> f1 <- function(x,digits=5) lapply(x, f2) >> f2 <- function(x) evalq(print(x+1,digits=digits),list(x=x),parent.frame(2)) >> f1(list(x1=1)) > Error in print.default(x + 1, digits = digits) : > object "digits" not found > > > On 5/27/07, Prof Brian Ripley <[EMAIL PROTECTED]> wrote: >> The meaning of parent.frame depends on where it is evaluated. So one >> should not expect it to do the same thing in two equivalent expressions >> (and nor should one expect deparse to do so, for example). >> >> A pretty close analogy is that using a symbolic link in a file system is >> equivalent to using the original file path, at least until you try '..' or >> 'pwd' on the path. (In the case of 'pwd' it depends on the OS: POSIX >> only requires '_an_ absolute pathname'.) >> >> On Sun, 27 May 2007, ronggui wrote: >> >> > The help page of eval says: The 'evalq' form is equivalent to >> > 'eval(quote(expr), ...)'. But the following is not equivalent. Can >> > anyone give me some explaination? Thanks very much. >> > >> >> f1 <- function(x,digits=5) lapply(x, f2) >> >> f2 <- function(x) >> eval(quote(print(x+1,digits=digits)),list(x=x),parent.frame(2)) >> >> f1(list(x1=1)) >> > [1] 2 >> > $x1 >> > [1] 2 >> > >> >> >> >> f1 <- function(x,digits=5) lapply(x, f2) >> >> f2 <- function(x) >> evalq(print(x+1,digits=digits),list(x=x),parent.frame(2)) >> >> f1(list(x1=1)) >> > Error in print.default(x + 1, digits = digits) : >> > object "digits" not found >> >> -- >> Brian D. Ripley, [EMAIL PROTECTED] >> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ >> University of Oxford, Tel: +44 1865 272861 (self) >> 1 South Parks Road, +44 1865 272866 (PA) >> Oxford OX1 3TG, UK Fax: +44 1865 272595 >> > > > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch 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.