[R] lattice package: line end style

[Peter Ehlers]

What a dummy I am. It just occurred to me that you can set
grid graphical parameters with par.settings.

cloud(your stuff,
       par.settings = list(grid.pars = list(lineend = "butt")))

  -Peter Ehlers


On 2010-04-06 14:53, Peter Ehlers wrote:
> On 2010-04-06 7:28, Daniel Alcock wrote:
>> First, apologies for no example data but I don't think it's needed in
>> this case,
>>
>> Q: Can (and if so how ) the line end style be changed for 'cloud' plots?
>>
>> I've tried par(lend=2), trellis.par.set(add.line = list(lend=2)) and
>> much googling but to no avail
>>
>
> You can't use 'lend' because it's not an add.line component. What
> you need is the grid graphics parameter 'lineend' which is
> ultimately used in lsegments().
>
> Here's a crude way to possible achieve what you need.
> (I'm still getting to grips with grid graphics.)
> This will replace panel.cloud and panel.3dscatter
> with very minor modifications.
>
> 1. make a copy of panel.3dscatter
> You should find, near the end, a call to lsegments() that
> ends with:
>
> lwd = lwd[ord])
>
> replace that line with:
>
> lwd = lwd[ord], ...)
>
> This will permit passing grid graphics parameters to gpar() in
> lsegments().
>
> (I think that all we really need is for Deepayan to make this
> change to panel.3dscatter; I suspect that this was an oversight,
> but there may well be good reasons.)
>
> 2. Save your copy as mypanel.3dscatter and set its environment to
> lattice's namespace:
>
> environment(mypanel.3dscatter) <- environment(xyplot)
>
> 3. Make a copy of panel.cloud
> Change the default argument for panel.3d.cloud from
> "panel.3dscatter" to "mypanel.3dscatter" and save the
> modified function to mypanel.cloud and set its environment
> as above.
>
> Now you should be able to call cloud:
>
> cloud(z ~ x*y | etc, panel = "mypanel.cloud", lineend = "square")
>
> Your choice are "round" (default), "butt" and "square".
>
>
> -Peter Ehlers
>
>> Thanks in advance
>>
>> Dan
>>
>> P.S. the reason for this is that the round end looks bad at lwd=3 or
>> more
>>
>> Daniel Alcock
>> Malaria Genetics (T112)
>> Wellcome Trust Sanger Institute
>> Cambridge
>> CB10 1SA
>> UK
>> +44 (0)1223 834244 ext. 4994
>> "The most exciting phrase to hear in science, the one that heralds new
>> discoveries, is not Eureka! But rather, "hmm.... that's funny...." --
>> Isaac Asimov
>>
>>
>>
>>
>

-- 
Peter Ehlers
University of Calgary