[R] lattice: how to use a log scale on the x-axis with the bwplot function

[Deepayan Sarkar]

Log-scales for the "factor" variable in bwplot() is not allowed.

You could, however, use the panel function panel.bwplot() with
xyplot(num ~ num). The potential problem with that is the box widths,
which panel.bwplot() will not know how to compute.

See if the following gives you a reasonable starting point:

DF <- within(DF, m <- tapply(y, groups, mean))
xyplot(y ~ m, DF, scales = list(log = TRUE),
       panel = panel.bwplot, horizontal = FALSE,
       box.width = .0001)

Best,
-Deepayan

On Sat, Dec 10, 2022 at 7:46 PM Laurent Rhelp <LaurentRHelp using free.fr> wrote:
>
> Dear R-Help list,
>
>     I would like to use bwplot from the lattice package with a log scale
> both on
> the x-axis and the y-axis but I do not know how to do that because I do
> not know
> how to change the factor x-axis in a numeric x-axis.
>
>   Here is my example:
>
>
> library(lattice)
>
> # the mock data
> y <- runif(100000,min=0, max=500)
> x <- seq(0,500,length=length(y))
> # I cut the x variable to create a factor variable in order to calculate
> the boxes
> groups <- cut(x,10,ordered_result = TRUE)
> # creating the dataframe for the lattice functions
> DF <- data.frame( x= x , y = y, groups = groups)
>
>
> ## ok for xyplot
> xyplot(   y ~ x
>            , data=DF
>            , scales = list(
>              y = list(log=T)
>              , x = list(log=T)
>
>            )
> )
>
> ## ok for bwplot with the log scale for the y-axis
> bwplot( y ~ groups
>            , data=DF
>            , scales = list(
>              y = list(log=T)
>              #     , x = list(log=T)
>
>            )
> )
>
>
>
> ## Non ok for bwplot with the log scale for the x-axis
> bwplot( y ~ groups
>          , data=DF
>          , scales = list(
>                y = list(log=T)
>              , x = list(log=T)
>
>          )
> )
> which gives an error because the x-axis is a factor, I would like to
> replace it
> for the display by the meddle of every class for example and put a log
> scale on the x-axis.
>
> Thank you for your help
> Best regards
> Laurent
>
>
>
> --
> Cet e-mail a été vérifié par le logiciel antivirus d'Avast.
> www.avast.com
>
> ______________________________________________
> R-help using 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.