| warning {base} | R Documentation |
Generates a warning message that corresponds to its argument(s) and (optionally) the expression or function from which it was called.
warning(..., call. = TRUE) suppressWarnings(expr)
... |
character vectors (which are pasted together with no
separator), a condition object, or NULL. |
call. |
logical, indicating if the call should become part of the warning message. |
expr |
expression to evaluate. |
The result depends on the value of
options("warn") and on handlers established in the
executing code.
warning signals a warning condition by (effectively) calling
signalCondition. If there are no handlers or if all handlers
return, then the value of warn is used to determine the
appropriate action. If warn is negative warnings are
ignored; if it is zero they are stored and printed after the
top–level function has completed; if it is one they are printed as
they occur and if it is 2 (or larger) warnings are turned into
errors.
If warn is zero (the default), a top-level variable
last.warning is created. It contains the warnings which can be
printed via a call to warnings.
Warnings will be truncated to getOption("warning.length")
characters, default 1000.
While the warning is being processed, a muffleWarning restart
is available. If this restart is invoked with invokeRestart,
then warning returns immediately.
suppressWarnings evaluates its expression in a context that
ignores all warnings.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
stop for fatal errors,
warnings,
and options with argument warn=.
testit <- function() warning("testit")
testit() ## shows call
testit <- function() warning("problem in testit", call. = FALSE)
testit() ## no call
suppressWarnings(warning("testit"))