Controlling line-join style in Lattice

R users,

I am creating a series of scatterplots with Lattice's xyplot().  Some of the plotting symbols are squares with thick borders.  The corners of the squares are rounded by default; I would like them to be square.  In base graphics this is easily done with par(ljoin = "mitre"), and in grid graphics with gpar(linejoin = "mitre").  Is there an analogous parameter in Lattice?  Passing ljoin as an argument to xyplot() or panel functions doesn't seem to work, and I can't find anything promising in lattice.par.get().

Thanks,
Andrew Morgan
Department of Genetics
University of North Carolina - Chapel Hill

You can set grid parameters in the grid.pars component of
trellis.par.get().

   x <- 1:4; y <- c(1,3,2,4)
   xyplot(y ~ x, type = "l", lwd = 20)  # default linejoin

   ## set linejoin to 'mitre'
   trellis.par.set(grid.pars = list(linejoin = "mitre"))
   xyplot(y ~ x, type = "l", lwd = 20)

Peter Ehlers

On 2012-08-22 11:09, Morgan, Andrew Parker wrote:

R users,

I am creating a series of scatterplots with Lattice's xyplot().  Some of the plotting symbols are squares with thick borders.  The corners of the squares are rounded by default; I would like them to be square.  In base graphics this is easily done with par(ljoin = "mitre"), and in grid graphics with gpar(linejoin = "mitre").  Is there an analogous parameter in Lattice?  Passing ljoin as an argument to xyplot() or panel functions doesn't seem to work, and I can't find anything promising in lattice.par.get().

Thanks,
Andrew Morgan
Department of Genetics
University of North Carolina - Chapel Hill