traceback                package:base                R Documentation

Print Call Stack of Last Error

Description:

     `traceback()' prints the call stack of the last error, i.e., the
     sequence of calls that lead to the error.  This is useful when an
     error occurs with an unidentifiable error message. This stack is
     stored as a list in `.Traceback', which `traceback' prints in a
     user-friendly format.

Usage:

     traceback()

Value:

     `traceback()' returns nothing, but prints the deparsed call stack
     deepest call first.  The calls may print on more that one line,
     and the first line is labelled by the frame number.

Examples:

     foo <- function(x) { print(1); bar(2) }
     bar <- function(x) { x + a.variable.which.does.not.exist }

     foo(2) # gives a strange error
     traceback()
     ## 2: bar(2)
     ## 1: foo(2)
     bar
     ## Ah, this is the culprit ...

