Add interpolate option to geom/annotation_raster.

Fixes #412
tidyverse · Apr 12, 2012 · b21b18b · b21b18b
1 parent b49056b
commit b21b18b
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Showing 5 changed files with 49 additions and 11 deletions.
diff --git a/NEWS b/NEWS
@@ -1,3 +1,6 @@
+* `geom_raster` and `annotation_raster` gain new `interpolate` argument for
+  controlling whether or not rasters are interpolated
+
 * Added `plot` as an alias for `print` for ggplot objects.
 
 * Visual tests have been moved to /visual_test and modified to work with the

diff --git a/R/annotation-raster.r b/R/annotation-raster.r
@@ -16,6 +16,8 @@ NULL
 #'   location of raster
 #' @param ymin,ymax y location (in data coordinates) giving vertical
 #'   location of raster
+#' @param interpolate If \code{TRUE} interpolate linearly, if \code{FALSE} 
+#'   (the default) don't interpolate.
 #' @export
 #' @examples
 #' # Generate data
@@ -26,11 +28,20 @@ NULL
 #' qplot(mpg, wt, data = mtcars) +
 #'   annotation_raster(rainbow, -Inf, Inf, -Inf, Inf) + 
 #'   geom_point()
-annotation_raster <- function (raster, xmin, xmax, ymin, ymax) { 
+#'
+#' rainbow2 <- matrix(hcl(seq(0, 360, length = 10), 80, 70), nrow = 1)
+#' qplot(mpg, wt, data = mtcars) +
+#'   annotation_raster(rainbow2, -Inf, Inf, -Inf, Inf) + 
+#'   geom_point()
+#' rainbow2 <- matrix(hcl(seq(0, 360, length = 10), 80, 70), nrow = 1)
+#' qplot(mpg, wt, data = mtcars) +
+#'   annotation_raster(rainbow2, -Inf, Inf, -Inf, Inf, interpolate = TRUE) + 
+#'   geom_point()
+annotation_raster <- function (raster, xmin, xmax, ymin, ymax, interpolate = FALSE) { 
   raster <- as.raster(raster)
   GeomRasterAnn$new(geom_params = list(raster = raster, xmin = xmin, 
-    xmax = xmax, ymin = ymin, ymax = ymax), stat = "identity", 
-    position = "identity", data = NULL, inherit.aes = TRUE)
+    xmax = xmax, ymin = ymin, ymax = ymax, interpolate = interpolate), 
+    stat = "identity", position = "identity", data = NULL, inherit.aes = TRUE)
 }
 
 GeomRasterAnn <- proto(GeomRaster, {
@@ -40,7 +51,7 @@ GeomRasterAnn <- proto(GeomRaster, {
   }
 
   draw_groups <- function(., data, scales, coordinates, raster, xmin, xmax,
-    ymin, ymax, ...) {
+    ymin, ymax, interpolate = FALSE, ...) {
     if (!inherits(coordinates, "cartesian")) {
       stop("annotation_raster only works with Cartesian coordinates", 
         call. = FALSE)
@@ -53,6 +64,6 @@ GeomRasterAnn <- proto(GeomRaster, {
 
     rasterGrob(raster, x_rng[1], y_rng[1], 
       diff(x_rng), diff(y_rng), default.units = "native", 
-      just = c("left","bottom"), interpolate = FALSE)
+      just = c("left","bottom"), interpolate = interpolate)
   }
 })
diff --git a/R/geom-raster.r b/R/geom-raster.r
@@ -16,6 +16,8 @@ NULL
 #' @param hjust,vjust horizontal and vertical justification of the grob.  Each
 #'   justification value should be a number between 0 and 1.  Defaults to 0.5 
 #'   for both, centering each pixel over its data location.
+#' @param interpolate If \code{TRUE} interpolate linearly, if \code{FALSE} 
+#'   (the default) don't interpolate.
 #' @export
 #' @examples
 #' \donttest{
@@ -28,6 +30,9 @@ NULL
 #'  df
 #' }
 #' qplot(x, y, data = pp(20), fill = z, geom = "raster")
+#' # Interpolation worsens the apperance of this plot, but can help when 
+#' # rendering images.
+#' qplot(x, y, data = pp(20), fill = z, geom = "raster", interpolate = TRUE)
 #'
 #' # For the special cases where it is applicable, geom_raster is much
 #' # faster than geom_tile:
@@ -44,11 +49,11 @@ NULL
 #' # zero padding
 #' ggplot(df, aes(x, y, fill = z)) + geom_raster(hpad = 0, vpad = 0)
 #' }
-geom_raster <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity", hjust = 0.5, vjust = 0.5, ...) { 
+geom_raster <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity", hjust = 0.5, vjust = 0.5, interpolate = FALSE, ...) { 
   stopifnot(is.numeric(hjust), length(hjust) == 1)
   stopifnot(is.numeric(vjust), length(vjust) == 1)
 
-  GeomRaster$new(mapping = mapping, data = data, stat = stat, position = position, hjust = hjust, vjust = vjust, ...)
+  GeomRaster$new(mapping = mapping, data = data, stat = stat, position = position, hjust = hjust, vjust = vjust, interpolate = interpolate, ...)
 }
 
 GeomRaster <- proto(Geom, {
@@ -68,7 +73,7 @@ GeomRaster <- proto(Geom, {
     df
   }
 
-  draw <- function(., data, scales, coordinates, hjust = 0.5, vjust = 0.5, ...) {
+  draw <- function(., data, scales, coordinates, hjust = 0.5, vjust = 0.5, interpolate = FALSE, ...) {
     if (!inherits(coordinates, "cartesian")) {
       stop("geom_raster only works with Cartesian coordinates", call. = FALSE)
     }
@@ -83,7 +88,7 @@ GeomRaster <- proto(Geom, {
 
     rasterGrob(raster, x = mean(x_rng), y = mean(y_rng), 
       width = diff(x_rng), height = diff(y_rng), 
-      default.units = "native", interpolate = FALSE)
+      default.units = "native", interpolate = interpolate)
   }
 
 

diff --git a/man/annotation_raster.Rd b/man/annotation_raster.Rd
@@ -2,7 +2,8 @@
 \alias{annotation_raster}
 \title{Annotation: High-performance rectangular tiling.}
 \usage{
-  annotation_raster(raster, xmin, xmax, ymin, ymax)
+  annotation_raster(raster, xmin, xmax, ymin, ymax,
+    interpolate = FALSE)
 }
 \arguments{
   \item{raster}{raster object to display}
@@ -12,6 +13,9 @@
 
   \item{ymin,ymax}{y location (in data coordinates) giving
   vertical location of raster}
+
+  \item{interpolate}{If \code{TRUE} interpolate linearly,
+  if \code{FALSE} (the default) don't interpolate.}
 }
 \description{
   This is a special version of \code{\link{geom_raster}}
@@ -33,5 +37,14 @@ qplot(mpg, wt, data = mtcars) +
 qplot(mpg, wt, data = mtcars) +
   annotation_raster(rainbow, -Inf, Inf, -Inf, Inf) +
   geom_point()
+
+rainbow2 <- matrix(hcl(seq(0, 360, length = 10), 80, 70), nrow = 1)
+qplot(mpg, wt, data = mtcars) +
+  annotation_raster(rainbow2, -Inf, Inf, -Inf, Inf) +
+  geom_point()
+rainbow2 <- matrix(hcl(seq(0, 360, length = 10), 80, 70), nrow = 1)
+qplot(mpg, wt, data = mtcars) +
+  annotation_raster(rainbow2, -Inf, Inf, -Inf, Inf, interpolate = TRUE) +
+  geom_point()
 }
 
diff --git a/man/geom_raster.Rd b/man/geom_raster.Rd
@@ -4,14 +4,17 @@
 \usage{
   geom_raster(mapping = NULL, data = NULL,
     stat = "identity", position = "identity", hjust = 0.5,
-    vjust = 0.5, ...)
+    vjust = 0.5, interpolate = FALSE, ...)
 }
 \arguments{
   \item{hjust,vjust}{horizontal and vertical justification
   of the grob.  Each justification value should be a number
   between 0 and 1.  Defaults to 0.5 for both, centering
   each pixel over its data location.}
 
+  \item{interpolate}{If \code{TRUE} interpolate linearly,
+  if \code{FALSE} (the default) don't interpolate.}
+
   \item{mapping}{The aesthetic mapping, usually constructed
   with \code{\link{aes}} or \code{\link{aes_string}}. Only
   needs to be set at the layer level if you are overriding
@@ -55,6 +58,9 @@ pp <- function (n,r=4) {
  df
 }
 qplot(x, y, data = pp(20), fill = z, geom = "raster")
+# Interpolation worsens the apperance of this plot, but can help when
+# rendering images.
+qplot(x, y, data = pp(20), fill = z, geom = "raster", interpolate = TRUE)
 
 # For the special cases where it is applicable, geom_raster is much
 # faster than geom_tile: