Hmm... still not quite what I was hoping for... but thanks anyway.
I would like to have the output in the following form:
f(1)
$result
[1] 0
$warning
[1] NULL # or ""
$error
[1] NULL # or ""
f(-1)
$result
[1] NaN
$warning
[1] "Warning in log(-1) : NaNs produced" # or something similar
$error
[1] NULL # or ""
f("a")
$result
[1] NULL # or NA
$warning
[1] NULL # or ""
$error
[1] "Error in log("a") : Non-numeric argument to mathematical function"
Has anyone done that before? I think it's quite a natural problem although I could not find a solution online (dealing with *both* warnings *and* errors).
Cheers,
Marius