Re: histogram() with "Date" class?

> On 5/8/08, Ola Caster <ola.caster@...> wrote:
> > Dear help list,
> >
> >  Is it possible to draw lattice histograms (i.e. use the histogram()
> function
> >  and not the hist() function) with objects of class "Date"?
>
> Sort of. The default calculation of 'breaks' doesn't work, so
>
> histogram(~date, data=my.data)
>
> will currently fail (I will fix this in the next update). However,
>
> histogram(~date, data=my.data, breaks = 10)
> histogram(~date, data=my.data, breaks = "fd")
>
> etc., should work. The help page for histogram is somewhat ambiguous; it
> says:
>
>  breaks:
>
>          [...]
>
>          Other valid values
>          of 'breaks' are those of the 'breaks' argument in 'hist'.
>          This allows specification of 'breaks' as an integer giving
>          the number of bins (similar to 'nint'), as a character string
>          denoting a method, and as a function.
>
> What is meant here is that valid values of breaks in 'hist.default'
> will work, not those for any other methods. In particular, breaks =
> "months" will not work.
>
> -Deepayan
>
> >  I've tried solutions like
> >
> >  histogram(~date, data=my.data, breaks="months")
> >
> >  but it doesn't seem to work.
> >
> >  Any suggestions are welcome.
> >
> >  Many thanks
> >  Ola Caster
>