stat_density

# Quick hack for a bug with the plot range in ggplot2's stat_density

require(ggplot2)
require(proto)

# Renamed to stat_density2 so as to not interfere with the ggplot2 package
stat_density2 <- function (mapping = NULL, data = NULL, geom = "area", position = "stack",
                          adjust = 1, kernel = "gaussian", trim = FALSE, na.rm = FALSE, ...) {
    StatDensity2$new(mapping = mapping, data = data, geom = geom, position = position,
                    adjust = adjust, kernel = kernel, trim = trim, na.rm = na.rm, ...)
}

# Also renamed, and added ggplot2::: in front of stat as this is run outside of the package
StatDensity2 <- proto(ggplot2:::Stat, {
    objname <- "density"

    calculate <- function(., data, scales, adjust=1, kernel="gaussian", trim=FALSE, na.rm = FALSE, ...) {
        data <- remove_missing(data, na.rm, "x", name = "stat_density2",
                               finite = TRUE)

        n <- nrow(data)
        if (n < 3) return(data.frame())
        if (is.null(data$weight)) data$weight <- rep(1, n) / n

        range <- scale_dimension(scales$x, c(0, 0))
        xgrid <- seq(range[1], range[2], length=200)

        # The Doc says that the 'trim' parameter works like 'cut' in density. This is not what
        #   happens however. As a quick fix I just removed the range here, as this trims the range
        #   without respecting the 'trim' parameter.
        dens <- density(data$x, adjust=adjust, kernel=kernel, weight=data$weight) # from=range[1], to=range[2]
        densdf <- as.data.frame(dens[c("x","y")])

        densdf$scaled <- densdf$y / max(densdf$y, na.rm = TRUE)
        if (trim) densdf <- subset(densdf, x > min(data$x, na.rm = TRUE) & x < max(data$x, na.rm = TRUE))

        densdf$count <- densdf$y * n
        rename(densdf, c(y = "density"))
    }

    default_geom <- function(.) GeomArea
    default_aes <- function(.) aes(y = ..density.., fill=NA)
    required_aes <- c("x")

})