Modernise geom_text

Author: hadley

R/geom-text.r

@@ -8,54 +8,47 @@
 #'   displayed as described in ?plotmath
 #' @export
 #' @examples
-#' \donttest{
 #' p <- ggplot(mtcars, aes(wt, mpg, label = rownames(mtcars)))
 #'
 #' p + geom_text()
 #' # Change size of the label
 #' p + geom_text(size=10)
-#' p <- p + geom_point()
 #'
 #' # Set aesthetics to fixed value
-#' p + geom_text()
-#' p + geom_point() + geom_text(hjust=0, vjust=0)
+#' p + geom_point() + geom_text(hjust = 0, vjust = 0)
 #' p + geom_point() + geom_text(angle = 45)
+#' p + geom_text(family = "Times New Roman")
 #'
 #' # Add aesthetic mappings
-#' p + geom_text(aes(colour=factor(cyl)))
-#' p + geom_text(aes(colour=factor(cyl))) + scale_colour_discrete(l=40)
+#' p + geom_text(aes(colour = factor(cyl)))
+#' p + geom_text(aes(colour = factor(cyl))) +
+#'   scale_colour_discrete(l = 40)
 #'
-#' p + geom_text(aes(size=wt))
-#' p + geom_text(aes(size=wt)) + scale_size(range=c(3,6))
+#' p + geom_text(aes(size = wt))
+#' # Scale height of text, rather than sqrt(height)
+#' p + geom_text(aes(size = wt)) + scale_radius(range = c(3,6))
 #'
 #' # You can display expressions by setting parse = TRUE.  The
 #' # details of the display are described in ?plotmath, but note that
 #' # geom_text uses strings, not expressions.
 #' p + geom_text(aes(label = paste(wt, "^(", cyl, ")", sep = "")),
 #'   parse = TRUE)
 #'
-#' # Add an annotation not from a variable source
-#' c <- ggplot(mtcars, aes(wt, mpg)) + geom_point()
-#' c + geom_text(data = NULL, x = 5, y = 30, label = "plot mpg vs. wt")
-#' # Or, you can use annotate
-#' c + annotate("text", label = "plot mpg vs. wt", x = 2, y = 15, size = 8, colour = "red")
-#'
-#' # You can specify family, fontface and lineheight
-#' p <- ggplot(mtcars, aes(x=wt, y=mpg, label=rownames(mtcars)))
-#' p + geom_text(fontface=3)
-#' p + geom_text(aes(fontface=am+1))
-#' p + geom_text(aes(family=c("serif", "mono")[am+1]))
-#' }
-geom_text <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity",
-parse = FALSE, ...) {
+#' # Add a text annotation
+#' p +
+#'   geom_text() +
+#'   annotate("text", label = "plot mpg vs. wt", x = 2, y = 15, size = 8, colour = "red")
+geom_text <- function(mapping = NULL, data = NULL, stat = "identity",
+                      position = "identity", parse = FALSE, ...) {
   GeomText$new(mapping = mapping, data = data, stat = stat, position = position,
-  parse = parse, ...)
+    parse = parse, ...)
 }
 
 GeomText <- proto(Geom, {
   objname <- "text"
 
   draw_groups <- function(., ...) .$draw(...)
+
   draw <- function(., data, scales, coordinates, ..., parse = FALSE, na.rm = FALSE) {
     data <- remove_missing(data, na.rm,
       c("x", "y", "label"), name = "geom_text")
@@ -65,27 +58,40 @@ GeomText <- proto(Geom, {
       lab <- parse(text = lab)
     }
 
-    with(coord_transform(coordinates, data, scales),
-      textGrob(lab, x, y, default.units="native",
-        hjust=hjust, vjust=vjust, rot=angle,
-        gp = gpar(col = alpha(colour, alpha), fontsize = size * .pt,
-          fontfamily = family, fontface = fontface, lineheight = lineheight))
+    coords <- coord_transform(coordinates, data, scales)
+    textGrob(
+      lab,
+      coords$x, coords$y, default.units = "native",
+      hjust = coords$hjust, vjust = coords$vjust,
+      rot = coords$angle,
+      gp = gpar(
+        col = alpha(coords$colour, coords$alpha),
+        fontsize = coords$size * .pt,
+        fontfamily = coords$family,
+        fontface = coords$fontface,
+        lineheight = coords$lineheight
+      )
     )
   }
 
   draw_legend <- function(., data, ...) {
     data <- aesdefaults(data, .$default_aes(), list(...))
-    with(data,
-      textGrob("a", 0.5, 0.5, rot = angle,
-      gp=gpar(col=alpha(colour, alpha), fontsize = size * .pt))
+    textGrob(
+      "a", 0.5, 0.5,
+      rot = data$angle,
+      gp = gpar(
+        col = alpha(data$colour, data$alpha),
+        fontsize = data$size * .pt
+      )
     )
   }
 
 
   default_stat <- function(.) StatIdentity
   required_aes <- c("x", "y", "label")
-  default_aes <- function(.) aes(colour="black", size=5 , angle=0, hjust=0.5,
-    vjust=0.5, alpha = NA, family="", fontface=1, lineheight=1.2)
+  default_aes <- function(.) aes(colour = "black", size = 5, angle = 0,
+    hjust = 0.5, vjust = 0.5, alpha = NA, family = "", fontface = 1,
+    lineheight = 1.2)
   guide_geom <- function(x) "text"
 
 })

man/geom_text.Rd

@@ -36,43 +36,35 @@ Textual annotations.
 \Sexpr[results=rd,stage=build]{ggplot2:::rd_aesthetics("geom", "text")}
 }
 \examples{
-\donttest{
 p <- ggplot(mtcars, aes(wt, mpg, label = rownames(mtcars)))
 
 p + geom_text()
 # Change size of the label
 p + geom_text(size=10)
-p <- p + geom_point()
 
 # Set aesthetics to fixed value
-p + geom_text()
-p + geom_point() + geom_text(hjust=0, vjust=0)
+p + geom_point() + geom_text(hjust = 0, vjust = 0)
 p + geom_point() + geom_text(angle = 45)
+p + geom_text(family = "Times New Roman")
 
 # Add aesthetic mappings
-p + geom_text(aes(colour=factor(cyl)))
-p + geom_text(aes(colour=factor(cyl))) + scale_colour_discrete(l=40)
+p + geom_text(aes(colour = factor(cyl)))
+p + geom_text(aes(colour = factor(cyl))) +
+  scale_colour_discrete(l = 40)
 
-p + geom_text(aes(size=wt))
-p + geom_text(aes(size=wt)) + scale_size(range=c(3,6))
+p + geom_text(aes(size = wt))
+# Scale height of text, rather than sqrt(height)
+p + geom_text(aes(size = wt)) + scale_radius(range = c(3,6))
 
 # You can display expressions by setting parse = TRUE.  The
 # details of the display are described in ?plotmath, but note that
 # geom_text uses strings, not expressions.
 p + geom_text(aes(label = paste(wt, "^(", cyl, ")", sep = "")),
   parse = TRUE)
 
-# Add an annotation not from a variable source
-c <- ggplot(mtcars, aes(wt, mpg)) + geom_point()
-c + geom_text(data = NULL, x = 5, y = 30, label = "plot mpg vs. wt")
-# Or, you can use annotate
-c + annotate("text", label = "plot mpg vs. wt", x = 2, y = 15, size = 8, colour = "red")
-
-# You can specify family, fontface and lineheight
-p <- ggplot(mtcars, aes(x=wt, y=mpg, label=rownames(mtcars)))
-p + geom_text(fontface=3)
-p + geom_text(aes(fontface=am+1))
-p + geom_text(aes(family=c("serif", "mono")[am+1]))
-}
+# Add a text annotation
+p +
+  geom_text() +
+  annotate("text", label = "plot mpg vs. wt", x = 2, y = 15, size = 8, colour = "red")
 }