"Deepayan Sarkar" <[EMAIL PROTECTED]> wrote: [...]
> Well, there are exceptions to this rule, but generally x and y, when > they are passed on to the panel function, are _already_ subsetted, so > x[subscripts] makes absolutely no sense. Note how your panel function > calls > panel.xyplot(x, y, ...) > without referring to subscripts at all. The subscripts argument is > there for other variables (e.g. if you were drawing confidence > intervals, and had a separate vector in your data specifying the > interval lengths). In your case, there are no other variables > involved, so just get rid of the subscripts. Thanks Deepayan, I was indeed quite confused about this. I realized I needed to limit the fitted line to the range of x values the line is fit to, so I changed to panel.curve: ---<---------------cut here---------------start-------------->--- xyplot(y ~ x | facA, groups = facB, data = toydf, panel.groups = function(x, y, ...) { panel.xyplot(x, y, ...) lindx <- which(y == max(y, na.rm = TRUE)) xleft <- mean(x[lindx], na.rm = TRUE) fit <- lm(y[x >= xleft] ~ x[x >= xleft]) panel.curve(coef(fit)[1] + (coef(fit)[2] * x), xleft, max(x, na.rm = TRUE)) }) ---<---------------cut here---------------end---------------->--- but can't find a way to color the line for each group differently. I tried passing a length-2 vector as a 'col' argument to panel.curve. Unfortunately it's only picking the first, so that both lines get colored the same. I'm not sure, but it seems as if I need to use 'panel.superpose' directly to do this, as the help page suggests the above would work? Cheers, -- Sebastian P. Luque ______________________________________________ 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