R help - Feb 2011 - lattice: Synchronizing key and lines; or: why is lty used as lwd in legend?

Dear latticists,

Getting legend and graph line types synchronized has been a challenge in
lattice; the last example below that works looks ridiculously ugly for such
a simple job, I am sure there is a more elegant solution.

When trying this out, I found a feature which I found confusing: why are
line types (lty) "translated" to line widths (lwd) in the legend? See
attached pdf in case this should not be reproducible on your computer. 

Dieter
 

Library(lattice)
os = OrchardSprays[OrchardSprays$rowpos <4,]
os$rowpos = as.factor(os$rowpos)

# Set it globally
# This is confusing: why is lty used as lwd in legend??
trellis.par.set(superpose.line =
list(col=c("blue","red","green"),
  lwd = 2, lty=c(1,4,6)))
xyplot(decrease ~ treatment, os, groups = rowpos,
       type = "a",  auto.key          list(space = "right",
points = FALSE, lines = TRUE))
dev.off()  

# To me, this seems to be the most consistent method if it worked.
s=
simpleTheme(lty=c(1,4,6),col=c("red","blue","green"),lwd=3)
xyplot(decrease ~ treatment, os, groups = rowpos,
       par.settings=s,
       type = "a",  auto.key          list(space = "right",
points = FALSE, lines = TRUE))

# !!! There must be an easier way to synchronize legend and plot
xyplot(decrease~treatment,data=os,groups=rowpos,
  type = "a",par.settings=s, 
  key = list(text=list(levels(os$rowpos)),
              lines=list(lty=s$superpose.line$lty,
              lwd=s$superpose.line$lwd,
              col= s$superpose.line$col)))

--------------------------------------------------------
R version 2.12.1 (2010-12-16)
Platform: i386-pc-mingw32/i386 (32-bit)

locale:
[1] LC_COLLATE=German_Germany.1252  LC_CTYPE=German_Germany.1252   
[3] LC_MONETARY=German_Germany.1252 LC_NUMERIC=C                   
[5] LC_TIME=German_Germany.1252    

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

other attached packages:
[1] lattice_0.19-17

loaded via a namespace (and not attached):
[1] grid_2.12.1  tools_2.12.1
>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: lwdAsLty.pdf
Type: application/pdf
Size: 5118 bytes
Desc: lwdAsLty.pdf
URL:
<https://stat.ethz.ch/pipermail/r-help/attachments/20110207/29743c31/attachment.pdf>

On Mon, Feb 7, 2011 at 1:10 PM, Dieter Menne
<dieter.menne at menne-biomed.de> wrote:
> Dear latticists,
>
> Getting legend and graph line types synchronized has been a challenge in
> lattice; the last example below that works looks ridiculously ugly for such
> a simple job, I am sure there is a more elegant solution.
>
> When trying this out, I found a feature which I found confusing: why are
> line types (lty) "translated" to line widths (lwd) in the legend?
See
> attached pdf in case this should not be reproducible on your computer.
This looks like a bug newly introduced in the recent lattice update,
your examples work as expected in earlier versions.

I will look into it. In the meantime, going back to version 0.19-13 may help.

-Deepayan
> Dieter
>
>
> Library(lattice)
> os = OrchardSprays[OrchardSprays$rowpos <4,]
> os$rowpos = as.factor(os$rowpos)
>
> # Set it globally
> # This is confusing: why is lty used as lwd in legend??
> trellis.par.set(superpose.line =
list(col=c("blue","red","green"),
> ?lwd = 2, lty=c(1,4,6)))
> xyplot(decrease ~ treatment, os, groups = rowpos,
> ? ? ? type = "a", ?auto.key > ? ? ? ? list(space =
"right", points = FALSE, lines = TRUE))
> dev.off()
>
> # To me, this seems to be the most consistent method if it worked.
> s=
simpleTheme(lty=c(1,4,6),col=c("red","blue","green"),lwd=3)
> xyplot(decrease ~ treatment, os, groups = rowpos,
> ? ? ? par.settings=s,
> ? ? ? type = "a", ?auto.key > ? ? ? ? list(space =
"right", points = FALSE, lines = TRUE))
>
> # !!! There must be an easier way to synchronize legend and plot
> xyplot(decrease~treatment,data=os,groups=rowpos,
> ?type = "a",par.settings=s,
> ?key = list(text=list(levels(os$rowpos)),
> ? ? ? ? ? ? ?lines=list(lty=s$superpose.line$lty,
> ? ? ? ? ? ? ?lwd=s$superpose.line$lwd,
> ? ? ? ? ? ? ?col= s$superpose.line$col)))
>
> --------------------------------------------------------
> R version 2.12.1 (2010-12-16)
> Platform: i386-pc-mingw32/i386 (32-bit)
>
> locale:
> [1] LC_COLLATE=German_Germany.1252 ?LC_CTYPE=German_Germany.1252
> [3] LC_MONETARY=German_Germany.1252 LC_NUMERIC=C
> [5] LC_TIME=German_Germany.1252
>
> attached base packages:
> [1] stats ? ? graphics ?grDevices datasets ?utils ? ? methods ? base
>
> other attached packages:
> [1] lattice_0.19-17
>
> loaded via a namespace (and not attached):
> [1] grid_2.12.1 ?tools_2.12.1
>>
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.
>
>