R help - Sep 2009 - dates with lattice graphics

Hi,
I'm trying to do something simple (I think) with lattice graphics.  I want
to have three xyplots in a single column, where the x axis for the three is
a date range and the y axes are numeric.

I tried doing the first chart, and ran into a problem.  When I enter:

xyplot (date ~ count)

I get a well formed plot with the date on the y axis, but when I enter:

xyplot (count ~ date)

I get: "Error in as.POSIXct.default(X[[2L]], ...) :
  do not know how to convert 'X[[2L]]' to class "POSIXlt"

Is there a way to create an xyplot with the dates on the x axis?

Thank you.

Larry

	[[alternative HTML version deleted]]

See last line to every message on r-help which in particular
asks for reproducible code and in this case means include
date and count.  Note ?dput

This work for me:

library(lattice)
tt <- as.POSIXct(Sys.Date() + 1:10)
y <- seq_along(tt)
xyplot(y ~ tt)

as does this:

library(zoo)
xyplot(zoo(cbind(y, y, y), tt))


On Mon, Sep 14, 2009 at 4:41 PM, Larry White <ljw1001 at gmail.com>
wrote:
> Hi,
> I'm trying to do something simple (I think) with lattice graphics. ?I
want
> to have three xyplots in a single column, where the x axis for the three is
> a date range and the y axes are numeric.
>
> I tried doing the first chart, and ran into a problem. ?When I enter:
>
> xyplot (date ~ count)
>
> I get a well formed plot with the date on the y axis, but when I enter:
>
> xyplot (count ~ date)
>
> I get: "Error in as.POSIXct.default(X[[2L]], ...) :
> ?do not know how to convert 'X[[2L]]' to class "POSIXlt"
>
> Is there a way to create an xyplot with the dates on the x axis?
>
> Thank you.
>
> Larry
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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>