[R] Problem with "date"-x-axis in lattice

[Deepayan Sarkar]

On 6/20/08, Henning Wildhagen <HWildhagen at gmx.de> wrote:
> Hello list,
>
>  i am trying to plot a continous variable y against a "date" variable, both
>  in one dataframe named "df", using a code like this
>
>  library(lattice)
>  plot1<-xyplot(y~date, data=df, type="b")
>
>  "date" is of class "Date", of course, format="%d.%m.%Y", and spans two
>  calendar years. The problem is that the x-axis is labeled with only one
>  tick mark corresponding to the year with century (%Y) of the second
>  calendar year.
>
>  Is there a way to define the increment of the x-axis tick marks?

Could you provide a reproducible example?

In general, the algorithm that computes tick locations for date-time
scales often performs inadequately. Presumably the algorithm could be
improved, but I don't know how (the current code is ripped off from
traditional graphics, which has similar problems). It may be simpler
to just specify 'at' locations manually in the 'scales' argument (see
?xyplot).

-Deepayan