[R] Set panel background color in a multi-group trellis plot

[crmontes at ncsu.edu]

Thanks,

I'll finaly figure it out.  It was not very intuitive though, even looking
at the help file.  The final code, for whom it might interest is:

 xyplot(Volume ~ Age|Farm,
                 groups       = Treatment,
                 data         = my_data,
                 panel        = panel.superpose,
                 panel.groups =  function(x,y, group.number, ...)
                   {
                     if (group.number == 1)panel.fill(col = "white")
                     panel.grid(col = "gray",lty = 2)
                     panel.xyplot(x,y,...)
                  }

Cristián Montes
NCState University


> Read ?panel.superpose carefully and pay attention to the comments about
> the
> group.number argument passed to panel.groups. You can test the value of
> this
> argument and adjust the plot accordingly.
>
>
>
> Bert Gunter
> Genentech Nonclinical Statistics
> 7-7374
>
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On
> Behalf Of crmontes at ncsu.edu
> Sent: Friday, November 30, 2007 8:50 AM
> To: r-help at r-project.org
> Subject: [R] Set panel background color in a multi-group trellis plot
>
> Hi everyone,
>
> I am trying to change some of the default colors in a
> multipanel-multigroup lattice graphic, but when I change the panel color
> to white, the only group that is plotted is the last one, as panel.fill
> overwrites all the previous ones.  Is there any way to set the panel
> background color for the first panel to a color and keep the rest
> transparent?
>
> My code looks like this:
>
> #first set defaults for getting more distinct symbols
> superp.symbol <- trellis.par.get("superpose.symbol")
> superp.symbol$pch = 15:21
> superp.symbol$cex = 1.5
> trellis.par.set("superpose.symbol", superp.symbol)
>
> #set the default for the colors in the symbols
> superp.lines <- trellis.par.get("superpose.line")
> superp.lines$lty <- 1:6
> superp.lines$lwd <- 1.5
> trellis.par.set("superpose.line", superp.lines)
>
> #set the device color to lightblue
> trellis.par.set("background", list(col = "lightblue"))
>
>
> xyplot(Volume ~ Age|Farm,
>                 groups       = Treatment,
>                 data         = my_data,
>                 panel        = panel.superpose,
>                 panel.groups =  function(x,y, ...)
>                   {
>                     panel.fill(col = "white")
>                     panel.grid(col = "gray",lty = 2)
>                     panel.xyplot(x,y,...)
>                  }
>