[R] POSIXct dates on x-axis using xyplot

[jim holtman]

I am using 'xyplot' in lattice to plot some data where the x-axis is a
POSIXct date.  I have data which spans a 6 month period, but when I
plot it, only the last month is printed on the right hand side of the
axis.  I would have expected that at least I would have a beginning
and an ending point so that I have a point of reference as to the time
that the data spans.  Here is some test data.


> # create test data
> dates <- seq(as.POSIXct('2006-01-03'), as.POSIXct('2006-06-26'), by='1 week')
> my.data <- seq(1, length=length(dates))
> require(lattice)
[1] TRUE
> # plot only shows a single month ("Jul" on the right).  Would have
> # expected at least the beginning and the ending month since this spans
> # a 6 month period
> pdf('/test.pdf')
> xyplot(my.data ~ dates)
> dev.off()
windows
      2
> sessionInfo()
R version 2.5.1 (2007-06-27)
i386-pc-mingw32

locale:
LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
States.1252;LC_MONETARY=English_United
States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252

attached base packages:
[1] "stats"     "graphics"  "grDevices" "utils"     "datasets"  "methods"
[7] "base"

other attached packages:
 lattice
"0.16-5"
> Sys.info()
                      sysname                       release
                    "Windows"                      "NT 5.1"
                      version                      nodename
"(build 2600) Service Pack 2"                  "JIM-LAPTOP"
                      machine                         login
                        "x86"                 "jim holtman"
                         user
                "jim holtman"
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?