Modifying Line Properties in panel.locfit

In principle one should be able to specify line properties to the panel functions, as in 
xyplot(accel ~ distance | Magnitude, data = Earthquake,
       scales = list(log = 2), col.line = "grey", lwd = 2,
       panel = function(...) {
           panel.xyplot(...)
           panel.abline(reg = coef)
           panel.loess(..., lty = 2)
       },
       xlab = "Distance From Epicenter (km)",
       ylab = "Maximum Horizontal Acceleration (g)")
Unfortunately panel.locfit does not seem to use the lattice parameters for determining line properties. Also, panel.locfit draws both points and the smooth, in contrast to panel.loess which only draws the line. This may make sense in the future to support alternative rendering of censored and uncensored points, but it might be better to make it optional.

Luke Tierney 2008-09-18