[Rd] Plot Dates (PR#2737)

[Uwe Ligges]

possolo at crd.ge.com wrote:
> 
> Full_Name: Antonio Possolo
> Version: 1.6.2
> OS: Linux & Windows2000
> Submission from: (NULL) (192.35.44.3)
> 
> x <- as.POSIXct(strptime(c("1993-5-11", "1994-11-23",
>                            "1995-7-8", "1996-10-15"), format="%Y-%m-%d"))
> y <- c(15, 32, 47, 61)
> plot(x, y, xlab="Date", ylab="Count")
> 
> Warns "parameter "ylab" couldn't be set in high-level plot() function",
> but generates the label as specified.
> Without 'ylab="Count"' no warning message is issued.

Not really a bug. It's a warning message, not an error, and the result
is as expected. The underlying problem has been discussed (at least
mentioned) several times - and I don't know an _optimal_ solution.

The warning comes from axis.POSIXct(1, x, ...) within plot.POSIXct(),
because axis() doesn't understand "ylab" which is passed by the ...
argument.

Uwe Ligges