How do I specify a "tight" y-axis, where the plot completely fills the y-axis range, inside the prepanel function? For example, consider the following code: require(lattice) set.seed(12345) x <- 1:1000 y <- cumsum(rnorm(length(x))) prepanel.test <- function(x, y, groups = NULL, subscripts = NULL, ...) { if (is.null(groups)) { result <- list(ylim = range(y)) } else { result <- list(ylim = range(y, finite = TRUE)) } return (result) } print(xyplot(y~x, prepanel = prepanel.test, type = 'l', grid = TRUE), split = c(1,1,1,2), more = TRUE) print(xyplot(y~x, ylim = range(y, finite = TRUE), type = 'l', grid = TRUE), split = c(1,2,1,2)) The top plot has extra whitespace at the top and bottom. Is there any way to eliminate this without having to specify 'ylim' directly in the call the 'xyplot'? (The reason I want to include this in the prepanel function is that I want to add conditioning and use the "combineLimits" function in the latticeExtra package.) Thanks. - Elliot [[alternative HTML version deleted]]