Lattice panel function for confidence intervals

This panel function is defined to plot confidence intervals in a multi-panel lattice display. Note, both lower and upper must be passed directly to xyplot as they will be passed down to the prepanel function.

panel.ci(x, y, subscripts, lower, upper, zl)

Arguments

x, y

Data from the call to xyplot.
subscripts

Variable used to created the juxtaposed panels.
lower, upper

95% lower and upper bounds of y.
zl

Logical indicating whether or not a horizontal dotted line at zero is desired.