Add stat_ksmooth()

Author: koheiw

DESCRIPTION

@@ -263,6 +263,7 @@ Collate:
     'stat-ellipse.R'
     'stat-function.R'
     'stat-identity.R'
+    'stat-ksmooth.R'
     'stat-manual.R'
     'stat-qq-line.R'
     'stat-qq.R'

NAMESPACE

@@ -254,6 +254,7 @@ export(StatEcdf)
 export(StatEllipse)
 export(StatFunction)
 export(StatIdentity)
+export(StatKsmooth)
 export(StatManual)
 export(StatQq)
 export(StatQqLine)
@@ -701,6 +702,7 @@ export(stat_ecdf)
 export(stat_ellipse)
 export(stat_function)
 export(stat_identity)
+export(stat_ksmooth)
 export(stat_manual)
 export(stat_qq)
 export(stat_qq_line)

R/stat-ksmooth.R

@@ -0,0 +1,32 @@
+#' @rdname Stat
+#' @format NULL
+#' @usage NULL
+#' @export
+StatKsmooth <- ggproto("StatKsmooth", Stat,
+                       required_aes = c("x", "y"),
+                       compute_group = function(data, scales, kernel = "box", bandwidth = 0.5) {
+                         as.data.frame(ksmooth(x = data$x, y = data$y, kernel = kernel, bandwidth = bandwidth))
+                       }
+)
+
+#' Apply kernel regression smoother
+#'
+#' @export
+#' @inheritParams layer
+#' @inheritParams geom_point
+#' @inheritParams stats::ksmooth
+#' @examples
+#' ggplot(economics, aes(date, psavert)) +
+#'   geom_point(alpha = 0.25) +
+#'   stat_ksmooth(bandwidth = 180, kernel = "normal")
+#'
+stat_ksmooth <- function(mapping = NULL, data = NULL, geom = "line",
+                         position = "identity", na.rm = FALSE, show.legend = NA,
+                         inherit.aes = TRUE, kernel = "box", bandwidth = 0.5,
+                         ...) {
+  layer(
+    stat = StatKsmooth, data = data, mapping = mapping, geom = geom,
+    position = position, show.legend = show.legend, inherit.aes = inherit.aes,
+    params = list(kernel = kernel, bandwidth = bandwidth, ...)
+  )
+}