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I was wondering how one is able to produce error messages in R, especially from within a function?

Cœur
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petermeissner
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    It's not exactly an answer (that's why I make it a comment here) to @petermeissner question, but surely often overlooked and helpful in this context: `geterrmessage()` returns the last error message, enabling you to pass error messages from other functions (used within your own functions) around. Quite helpful when used with `tryCatch`. – Matt Bannert Dec 23 '16 at 10:05

2 Answers2

128

Since you don't specify what you really want, all I just can say is take a look at

?message # prints a message but not stop execution
?warning # prints a warning message but not stop execution
?stop # stops execution of the current expression and executes an error action.
Jilber Urbina
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49

Simply include stop() inside your function/script

If you'd like an error message, include it inside stop() like so

stop("This is an error message")
stevec
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