[R] Does anybody know how to control the appearance of the end of the line in lattice?

[Duncan Mackay]

Hi

see
http://finzi.psych.upenn.edu/Rhelp10/2010-April/234441.html

The following I think works - its a bit rough - needs improving but saves 
closing the device.
xyplot(y2+y1~x,
        data=Source,
        par.settings = list(grid.pars = list(lineend = "butt")),
        #distribute.type=TRUE,
        y1 = Source$y1,
        y2=Source$y2,

         panel = function(x,y1,y2,...){

           panel.segments(x,y1, x,y2, gp = gpar(lineend="butt"), 
col=c("black"), lwd =20)

         }
)


Regards

Duncan

Duncan Mackay
Department of Agronomy and Soil Science
University of New England
ARMIDALE NSW 2351
Email home: mackay at northnet.com.au


At 06:23 9/08/2010, you wrote:
>Hi
>
>On 9/08/2010 7:49 a.m., George Chen wrote:
>>Hi All,
>>
>>I am plotting vertical lines using xyplot in lattice and type="h".
>>It works well, but the problem is that the tops of the lines are convex 
>>and the bottoms are concave.
>>Is there a way to flatten the tops and bottoms?
>
>You want to control the graphical parameter called "lineend", but I don't 
>think this is generally made available via trellis.par.set(). Also, trying 
>to set a default value via the 'grid.pars' argument, or via a viewport 
>with the 'draw.in' argument doesn't appear to work in this case (the 
>lineend may be hard coded in the internal code somewhere). The following 
>code (to be run AFTER your code) does the trick for your example ...
>
>library(grid)
>grid.gedit("segments", gp=gpar(lineend="butt"), grep=TRUE)
>
>... though I believe this will also make the ends of the tick marks on the 
>axes square (not obvious to the naked eye at the default size).
>
>Paul
>
>>Here's my code:
>>
>>Source<-matrix(1:30,10,3)
>>colnames(Source)<-c("x","y1","y2")
>>Source<-data.frame(Source)
>>
>>xyplot(y2+y1~x,
>>         data=Source,
>>         distribute.type=TRUE,
>>         type=c("h","h"),
>>         col=c("black","white"),
>>          lwd=20)
>>graphics.off()
>>
>>Thanks.
>>
>>George Chen
>>
>>______________________________________________
>>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.
>
>--
>Dr Paul Murrell
>Department of Statistics
>The University of Auckland
>Private Bag 92019
>Auckland
>New Zealand
>64 9 3737599 x85392
>paul at stat.auckland.ac.nz
>http://www.stat.auckland.ac.nz/~paul/
>
>______________________________________________
>R-help at r-project.org mailing list
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>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.
>