[R] xyplot() and controlling panel.polygon()

[Michael Kubovy]

Hi Deepayan,

Thanks for your advice. This is moving along, however:
The following is drawing the same polygons in each panel. I'm trying  
to get a different polygon (confidence band) for each group in each  
panel. That's why I thought I would need to pass groups and  
subscripts to the panel.groups

est <- c(1:4, 3:6, 7, 9, 11, 13, 12, 15, 18, 21)
cond <- rep(c('a','b'), each = 8)
grp <- rep(c('I', 'II'), each = 4, 2)
x <- rep(c(.5, .7, .9, 1.1), 4)
upper <- est + 1
lower = est - 1
data <- data.frame(est = est, x = x, cond = cond, grp = grp, upper =
upper, lower = lower)

my.panel.polygon <- function(..., font, fontface)
{
    panel.polygon(...)
}

xyplot(est ~ x | cond, group = grp, data = data, type = 'b',
     panel = function(x, y, ...){
         panel.superpose(c(x, rev(x)), c(upper, rev(lower)),
             panel.groups = 'my.panel.polygon', default.units =  
'native', ...)
         panel.xyplot(x, y, ...)
     }
)

It's pretty clear that panel.superpose is not getting its x and y  
values after they are split by group and panel.

_____________________________
Professor Michael Kubovy
University of Virginia
Department of Psychology
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