On Wed, 23 Mar 2022 09:38:34 +0000 "Garbade, Sven via R-help" <r-help at r-project.org> wrote:> cpl <- current.panel.limits()If you str() the return value of current.panel.limits() from the panel function with log-scaling enabled, you can see that it contains the logarithm of the y-values, as do the y values themselves. This is consistent with ?xyplot saying:>> Note that this is in reality a transformation of the data, not the >> axes. Other than the axis labeling, using this feature is no >> different than transforming the data in the formula; e.g., >> ?scales=list(x = list(log = 2))? is equivalent to ?y ~ log2(x)?....although it could be more explicit. If you take a logarithm of 10 and 500, lrect() should be able to produce a rectangle in the right place. -- Best regards, Ivan
thanks, this do the trick!
xyplot(y ~ x,
panel=function(x,y, ...) {
cpl <- current.panel.limits()
yseq <- log(c(100,1000))
panel.rect(xleft=cpl$xlim[1],
ybottom=yseq[1],
xright=cpl$xlim[2],
ytop=yseq[2],
fill="lightgray", border="lightgray",
alpha=.6)
panel.xyplot(x,y,...)
},
scales=list(y=list(log=2))
)
Best Regards, Sven
________________________________________
Von: Ivan Krylov <krylov.r00t at gmail.com>
Gesendet: Mittwoch, 23. M?rz 2022 11:33
An: Garbade, Sven via R-help
Cc: Garbade, Sven
Betreff: Re: [R] panel.rect and log scale in lattice plot
On Wed, 23 Mar 2022 09:38:34 +0000
"Garbade, Sven via R-help" <r-help at r-project.org> wrote:
> cpl <- current.panel.limits()
If you str() the return value of current.panel.limits() from the panel
function with log-scaling enabled, you can see that it contains the
logarithm of the y-values, as do the y values themselves. This is
consistent with ?xyplot saying:
>> Note that this is in reality a transformation of the data, not the
>> axes. Other than the axis labeling, using this feature is no
>> different than transforming the data in the formula; e.g.,
>> ?scales=list(x = list(log = 2))? is equivalent to ?y ~ log2(x)?.
...although it could be more explicit.
If you take a logarithm of 10 and 500, lrect() should be able to
produce a rectangle in the right place.
--
Best regards,
Ivan
On Wed, Mar 23, 2022 at 4:08 PM Ivan Krylov <krylov.r00t at gmail.com> wrote:> > On Wed, 23 Mar 2022 09:38:34 +0000 > "Garbade, Sven via R-help" <r-help at r-project.org> wrote: > > > cpl <- current.panel.limits() > > If you str() the return value of current.panel.limits() from the panel > function with log-scaling enabled, you can see that it contains the > logarithm of the y-values, as do the y values themselves. This is > consistent with ?xyplot saying: > > >> Note that this is in reality a transformation of the data, not the > >> axes. Other than the axis labeling, using this feature is no > >> different than transforming the data in the formula; e.g., > >> ?scales=list(x = list(log = 2))? is equivalent to ?y ~ log2(x)?. > > ...although it could be more explicit. > > If you take a logarithm of 10 and 500, lrect() should be able to > produce a rectangle in the right place.Right, "log scales" in lattice simply transform the data, unlike in traditional graphics. If it helps, I could change current.panel.limits() to return information on whether the data were transformed. For now, a roundabout way to detect this inside the panel function is to use trellis.last.object()$y.scales$log etc. Best, -Deepayan> > -- > Best regards, > Ivan > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.