| 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, immediate. = FALSE, domain = NULL) suppressWarnings(expr)
... |
zero or more objects which can be coerced to character (and which are pasted together with no separator) or a single condition object. |
call. |
logical, indicating if the call should become part of the warning message. |
immediate. |
logical, indicating if the call should be output
immediately, even if |
expr |
expression to evaluate. |
domain |
see |
The result depends on the value of
options("warn") and on handlers established in the
executing code.
If a condition object is supplied it should be the only argument, and further arguments will be ignored, with a message.
warning signals a warning condition by (effectively) calling
signalCondition. If there are no handlers or if all handlers
return, then the value of warn = getOption("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. Calling warning(immediate. = TRUE) turns warn <=
0 into warn = 1 for this call only.
If warn is zero (the default), a read-only 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, indicated by [... truncated].
While the warning is being processed, a muffleWarning restart
is available. If this restart is invoked with invokeRestart,
then warning returns immediately.
An attempt is made to coerce other types of inputs to warning
to character vectors.
suppressWarnings evaluates its expression in a context that
ignores all warnings.
The warning message as character string, invisibly.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
stop for fatal errors,
message for diagnostic messages,
warnings,
and options with argument warn=.
gettext for the mechanisms for the automated translation
of messages.
testit <- function() warning("testit")
testit() ## shows call
testit <- function() warning("problem in testit", call. = FALSE)
testit() ## no call
suppressWarnings(warning("testit"))