method.args for stat_quantile. Fixes #1289

Author: hadley

NEWS

@@ -63,8 +63,9 @@ ggplot2 1.0.1.9xxx
 * `geom_smooth()` is no longer so chatty. If you want to know what the deafult
   smoothing method is, look it up in the documentation! (#1247)
 
-* `geom_smooth()`/`stat_smooth()` no longer pass ... on to the
-  underlying model. Instead, put additional arguments in `method.args` (#1245).
+* `geom_smooth()`/`stat_smooth()` and `geom_quantile()`/`stat_quantile()` no
+  longer pass ... on to the underlying model. Instead, put additional arguments
+  in `method.args` (#1245, #1289).
 
 * `element_text()` gains a margins argument which allows you to add additional
   margins around text elements in the plot. The default themes have been

R/geom-quantile.r

@@ -8,6 +8,8 @@
 #' @export
 #' @inheritParams geom_point
 #' @inheritParams geom_path
+#' @param method.args List of additional arguments passed on to the modelling
+#'   function defined by \code{method}.
 #' @param geom,stat Use to override the default connection between
 #'   \code{geom_quantile} and \code{stat_quantile}.
 #' @examples
@@ -21,7 +23,7 @@
 #' m + geom_quantile(method = "rqss")
 #' # Note that rqss doesn't pick a smoothing constant automatically, so
 #' # you'll need to tweak lambda yourself
-#' m + geom_quantile(method = "rqss", lambda = 1)
+#' m + geom_quantile(method = "rqss", lambda = 0.1)
 #'
 #' # Set aesthetics to fixed value
 #' m + geom_quantile(colour = "red", size = 2, alpha = 0.5)

R/stat-quantile.r

@@ -13,8 +13,9 @@
 #' @rdname geom_quantile
 stat_quantile <- function(mapping = NULL, data = NULL, geom = "quantile",
                           position = "identity", quantiles = c(0.25, 0.5, 0.75),
-                          formula = NULL, method = "rq", na.rm = FALSE,
-                          show.legend = NA, inherit.aes = TRUE, ...) {
+                          formula = NULL, method = "rq", method.args = list(),
+                          na.rm = FALSE, show.legend = NA, inherit.aes = TRUE,
+                          ...) {
   layer(
     data = data,
     mapping = mapping,
@@ -27,6 +28,7 @@ stat_quantile <- function(mapping = NULL, data = NULL, geom = "quantile",
       quantiles = quantiles,
       formula = formula,
       method = method,
+      method.args = method.args,
       na.rm = na.rm
     ),
     params = list(...)
@@ -43,7 +45,8 @@ StatQuantile <- ggproto("StatQuantile", Stat,
 
   compute_group = function(data, scales, quantiles = c(0.25, 0.5, 0.75),
                            formula = NULL, xseq = NULL, method = "rq",
-                           lambda = 1, na.rm = FALSE, ...) {
+                           method.args = list(), lambda = 1, na.rm = FALSE,
+                           ...) {
     try_require("quantreg", "stat_quantile")
 
     if (is.null(formula)) {
@@ -70,12 +73,15 @@ StatQuantile <- ggproto("StatQuantile", Stat,
     method <- match.fun(method)
 
     plyr::ldply(quantiles, quant_pred, data = data, method = method,
-      formula = formula, weight = weight, grid = grid, ...)
+      formula = formula, weight = weight, grid = grid, method.args = method.args)
   }
 )
 
-quant_pred <- function(quantile, data, method, formula, weight, grid, ...) {
-  model <- method(formula, data = data, tau = quantile, weights = weight, ...)
+quant_pred <- function(quantile, data, method, formula, weight, grid,
+                       method.args = method.args) {
+  args <- c(list(quote(formula), data = quote(data), tau = quote(quantile),
+    weights = quote(weight)), method.args)
+  model <- do.call(method, args)
 
   grid$y <- stats::predict(model, newdata = grid)
   grid$quantile <- quantile

man/geom_quantile.Rd

@@ -12,8 +12,8 @@ geom_quantile(mapping = NULL, data = NULL, stat = "quantile",
 
 stat_quantile(mapping = NULL, data = NULL, geom = "quantile",
   position = "identity", quantiles = c(0.25, 0.5, 0.75), formula = NULL,
-  method = "rq", na.rm = FALSE, show.legend = NA, inherit.aes = TRUE,
-  ...)
+  method = "rq", method.args = list(), na.rm = FALSE, show.legend = NA,
+  inherit.aes = TRUE, ...)
 }
 \arguments{
 \item{mapping}{Set of aesthetic mappings created by \code{\link{aes}} or
@@ -66,6 +66,9 @@ the default plot specification, e.g. \code{\link{borders}}.}
 
 \item{method}{Quantile regression method to use.  Currently only supports
 \code{\link[quantreg]{rq}}.}
+
+\item{method.args}{List of additional arguments passed on to the modelling
+function defined by \code{method}.}
 }
 \description{
 This can be used as a continuous analogue of a geom_boxplot.
@@ -92,7 +95,7 @@ m + geom_quantile(quantiles = q10)
 m + geom_quantile(method = "rqss")
 # Note that rqss doesn't pick a smoothing constant automatically, so
 # you'll need to tweak lambda yourself
-m + geom_quantile(method = "rqss", lambda = 1)
+m + geom_quantile(method = "rqss", lambda = 0.1)
 
 # Set aesthetics to fixed value
 m + geom_quantile(colour = "red", size = 2, alpha = 0.5)