I am trying to create a lattice plot and would like to later, i.e. after
the plot is drawn, add a grey rectangle behind a portion of it.
The following works except that the rectrangle is on top of and
obscures a portion of the chart. I also tried adding col =
"transparent"
to the gpar list but that did not help -- I am on windows and
perhaps the windows device does not support transparency?
At any rate, how can I place the rectangle behind the plotted
points without drawing the rectangle first?
library(lattice)
library(grid)
trellis.unfocus()
x <- 1:10
xyplot(x ~ x | gl(2,1), layout = 1:2)
trellis.focus("panel", 1, 1)
grid.rect(w = .5, gp = gpar(fill = "light grey"))
trellis.unfocus()
Hi Gabor, On Sat, 29 Jul 2006 17:20:29 -0400, "Gabor Grothendieck" <ggrothendieck at gmail.com> wrote:> I am trying to create a lattice plot and would like to later, i.e. after > the plot is drawn, add a grey rectangle behind a portion of it. The > following works except that the rectrangle is on top of and obscures a > portion of the chart. I also tried adding col = "transparent" to the > gpar list but that did not help -- I am on windows and perhaps the > windows device does not support transparency? At any rate, how can I > place the rectangle behind the plotted points without drawing the > rectangle first?If you only need to draw the rectangle behind the points, why not 'panel.polygon' before 'panel.xyplot'? xyplot(x ~ x | gl(2, 1), layout=1:2, panel=function(x, y, ...) { panel.polygon(c(3, 3, 8, 8), c(0, 12, 12, 0), col=2) panel.xyplot(x, y, ...) }) Cheers, -- Seb
Hi Gabor Grothendieck wrote:> I am trying to create a lattice plot and would like to later, i.e. after > the plot is drawn, add a grey rectangle behind a portion of it. > The following works except that the rectrangle is on top of and > obscures a portion of the chart. I also tried adding col = "transparent" > to the gpar list but that did not help -- I am on windows and > perhaps the windows device does not support transparency?Correct.> At any rate, how can I place the rectangle behind the plotted > points without drawing the rectangle first? > > library(lattice) > library(grid) > trellis.unfocus() > x <- 1:10 > xyplot(x ~ x | gl(2,1), layout = 1:2) > trellis.focus("panel", 1, 1) > grid.rect(w = .5, gp = gpar(fill = "light grey")) > trellis.unfocus()The user-interface is a little rough, but this can be done by accessing the underlying grid objects. Here's an example, with explanatory bits interspersed ... # "grab" the lattice plot as a grid gTree # There are warnings, but they are ignorable latticeplot <- grid.grabExpr(print(xyplot(x ~ x | gl(2,1), layout = 1:2))) # Demonstrate that the gTree faithfully replicates the # original lattice plot (not necessary, just to to what's going on) grid.newpage() grid.draw(latticeplot) # Explore the gTree (just to to show what's going on) # Better user-interface would be nice here ... childNames(latticeplot) # Identify which children are which # (appropriate grob names would be nice here) lapply(latticeplot$children, class) # Identify where each child is drawn latticeplot$childrenvp lapply(latticeplot$children, "[[", "vp") # Add a rect (starts off on top of everything else) # NOTE that rect has to have correct vpPath plotwithrect <- addGrob(latticeplot, rectGrob(w = .5, gp = gpar(fill = "light grey"), vp=vpPath("plot1.toplevel.vp", "plot1.panel.1.1.vp"))) # Check this draws what we expect (just to show what's going on) grid.newpage() grid.draw(plotwithrect) # Reorder children to put rect at back # Appropriate user-interface would be nice here ... nc <- length(plotwithrect$childrenOrder) plotwithrect$childrenOrder <- plotwithrect$childrenOrder[c(nc, 1:(nc - 1))] # Final result grid.newpage() grid.draw(plotwithrect) Paul -- 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/
One thing you could try (probably as last resort, if someone comes up with a
better idea, use that) is to plot to an xfig device, then use xfig (or jfig) to
move the rectangle to the back, then convert it to whatever final graphics
format you want.
-----Original Message-----
From: r-help-bounces@stat.math.ethz.ch on behalf of Gabor Grothendieck
Sent: Sat 7/29/2006 3:20 PM
To: RHelp
Subject: [R] placing rectangle behind plot
I am trying to create a lattice plot and would like to later, i.e. after
the plot is drawn, add a grey rectangle behind a portion of it.
The following works except that the rectrangle is on top of and
obscures a portion of the chart. I also tried adding col =
"transparent"
to the gpar list but that did not help -- I am on windows and
perhaps the windows device does not support transparency?
At any rate, how can I place the rectangle behind the plotted
points without drawing the rectangle first?
library(lattice)
library(grid)
trellis.unfocus()
x <- 1:10
xyplot(x ~ x | gl(2,1), layout = 1:2)
trellis.focus("panel", 1, 1)
grid.rect(w = .5, gp = gpar(fill = "light grey"))
trellis.unfocus()
______________________________________________
R-help@stat.math.ethz.ch 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.
[[alternative HTML version deleted]]