Split geom_hline into geom and annotation (fixes #426)

DESCRIPTION

@@ -174,7 +174,6 @@ Collate:
     'stat-sum.r'
     'stat-summary.r'
     'stat-unique.r'
-    'stat-vline.r'
     'stat-ydensity.r'
     'summary.r'
     'templates.r'

NAMESPACE

@@ -171,7 +171,6 @@ export(scale_y_log10)
 export(scale_y_reverse)
 export(scale_y_sqrt)
 export(should_stop)
-export(stat_abline)
 export(stat_bin)
 export(stat_bin2d)
 export(stat_bindot)
@@ -181,7 +180,6 @@ export(stat_contour)
 export(stat_density)
 export(stat_density2d)
 export(stat_function)
-export(stat_hline)
 export(stat_identity)
 export(stat_qq)
 export(stat_quantile)
@@ -192,7 +190,6 @@ export(stat_summary_hex)
 export(stat_summary)
 export(stat_summary2d)
 export(stat_unique)
-export(stat_vline)
 export(stat_ydensity)
 export(theme_blank)
 export(theme_bw)

R/annotation.r

@@ -18,6 +18,8 @@
 #' @param ymin ymin position
 #' @param xmax xmax position
 #' @param ymax ymax position
+#' @param xintercept xintercept position
+#' @param yintercept yintercept position
 #' @param ... other arguments passed to geom as parameters
 #' @export
 #' @examples
@@ -27,11 +29,12 @@
 #' p + annotate("segment", x = 2.5, xend = 4, y = 15, yend = 25, colour = "blue")
 #' p + annotate("pointrange", x = 3.5, y = 20, ymin = 12, ymax = 28,
 #'   colour = "red", size = 1.5)
-annotate <- function(geom, x = NULL, y = NULL, xmin = NULL, xmax = NULL, ymin = NULL, ymax = NULL, ...) {
+annotate <- function(geom, x = NULL, y = NULL, xmin = NULL, xmax = NULL,
+  xintercept = NULL, ymin = NULL, ymax = NULL, yintercept = NULL, ...) {
 
   layer_data <- compact(list(
-    x = x, xmin = xmin, xmax = xmax, 
-    y = y, ymin = ymin, ymax = ymax
+    x = x, xmin = xmin, xmax = xmax, xintercept = xintercept,
+    y = y, ymin = ymin, ymax = ymax, yintercept = yintercept
   ))
 
   layer(

R/geom-abline.r

@@ -1,81 +1,30 @@
-#' Line specified by slope and intercept.
-#' 
-#' The abline geom adds a line with specified slope and intercept to the
-#' plot.
-#' 
-#' With its siblings \code{geom_hline} and \code{geom_vline}, it's useful for
-#' annotating plots.  You can supply the parameters for geom_abline, 
-#' intercept and slope, in two ways: either explicitly as fixed values, or
-#' in a data frame.  If you specify the fixed values
-#' (\code{geom_abline(intercept=0, slope=1)}) then the line will be the same
-#' in all panels.  If the intercept and slope are stored in the data, then 
-#' they can vary from panel to panel.  See the examples for more ideas.
-#'
-#' @seealso \code{\link{stat_smooth}} to add lines derived from the data,
-#'  \code{\link{geom_hline}} for horizontal lines,
-#'  \code{\link{geom_vline}} for vertical lines
-#'  \code{\link{geom_segment}}
-#' @param show_guide should a legend be drawn? (defaults to \code{FALSE})
-#' @inheritParams geom_point
+#' @rdname geom_hline
 #' @export
-#' @examples
-#' p <- qplot(wt, mpg, data = mtcars)
-#'
-#' # Fixed slopes and intercepts
-#' p + geom_abline() # Can't see it - outside the range of the data
-#' p + geom_abline(intercept = 20)
-#'
-#' # Calculate slope and intercept of line of best fit
-#' coef(lm(mpg ~ wt, data = mtcars))
-#' p + geom_abline(intercept = 37, slope = -5)
-#' p + geom_abline(intercept = 10, colour = "red", size = 2)
-#' 
-#' # See ?stat_smooth for fitting smooth models to data
-#' p + stat_smooth(method="lm", se=FALSE)
-#' 
-#' # Slopes and intercepts as data
-#' p <- ggplot(mtcars, aes(x = wt, y=mpg), . ~ cyl) + geom_point()
-#' df <- data.frame(a=rnorm(10, 25), b=rnorm(10, 0))
-#' p + geom_abline(aes(intercept=a, slope=b), data=df)
-#'
-#' # Slopes and intercepts from linear model
-#' library(plyr)
-#' coefs <- ddply(mtcars, .(cyl), function(df) { 
-#'   m <- lm(mpg ~ wt, data=df)
-#'   data.frame(a = coef(m)[1], b = coef(m)[2]) 
-#' })
-#' str(coefs)
-#' p + geom_abline(data=coefs, aes(intercept=a, slope=b))
-#' 
-#' # It's actually a bit easier to do this with stat_smooth
-#' p + geom_smooth(aes(group=cyl), method="lm")
-#' p + geom_smooth(aes(group=cyl), method="lm", fullrange=TRUE)
-#' 
-#' # With coordinate transforms
-#' p + geom_abline(intercept = 37, slope = -5) + coord_flip()
-#' p + geom_abline(intercept = 37, slope = -5) + coord_polar()
-geom_abline <- function (mapping = NULL, data = NULL, stat = "abline", position = "identity", show_guide = FALSE, ...) { 
+geom_abline <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity", show_guide = FALSE, ...) { 
   GeomAbline$new(mapping = mapping, data = data, stat = stat, position = position, show_guide = show_guide, ...)
 }
 
 GeomAbline <- proto(Geom, {
   objname <- "abline"
 
-  new <- function(., mapping = NULL, ...) {
-    mapping <- compact(defaults(mapping, aes(group = 1)))
-    class(mapping) <- "uneval"
-    .super$new(., ..., mapping = mapping, inherit.aes = FALSE)
-  }
-
-  draw <- function(., data, scales, coordinates, ...) {
+  draw <- function(., data, scales, coordinates, intercept = NULL, slope = NULL, ...) {
     ranges <- coord_range(coordinates, scales)
 
+    if (!is.null(intercept))
+      data$intercept <- intercept
+    if (!is.null(slope))
+      data$slope <- slope
+
     data$x    <- ranges$x[1]
     data$xend <- ranges$x[2]
     data$y    <- ranges$x[1] * data$slope + data$intercept
     data$yend <- ranges$x[2] * data$slope + data$intercept
 
-    GeomSegment$draw(unique(data), scales, coordinates)
+    if(nrow(data) > 1 && nrow(unique(data)) == 1)
+      message("There are ", nrow(data), " identical ablines. If you want just one line, use annontate(\"abline\") instead of geom_abline().")
+
+
+    GeomSegment$draw(data, scales, coordinates)
   }
 
   icon <- function(.) linesGrob(c(0, 1), c(0.2, 0.8))

R/geom-hline.r

@@ -1,63 +1,78 @@
-#' Horizontal line.
+#' Horizontal, vertical, and sloped lines.
 #'
-#' This geom allows you to annotate the plot with horizontal lines (see
-#' \code{\link{geom_vline}} and \code{\link{geom_abline}} for other types of
-#' lines).
+#' You can either add lines at specified positions with
+#' \code{annotate(geom="hline")} (or \code{vline} or \code{abline},
+#' or you can use variables from a data frame to specify the positions,
+#' using \code{geom_hline}.
 #'
-#' There are two ways to use it. You can either specify the intercept of 
-#' the line in the call to the geom, in which case the line will be in the
-#' same position in every panel. Alternatively, you can supply a different
-#' intercept for each panel using a data.frame. See the examples for the
-#' differences
+#' The \code{annotate} form is useful for adding individual lines to a plot,
+#' while the \code{geom} form is useful for drawing lines directly from the
+#' data
+#'
+#' For \code{geom_hline}, specify the y-intercept with \code{yintercept}.
+#'
+#' For \code{geom_vline}, specify the x-intercept with \code{xintercept}.
+#'
+#' For \code{geom_abline}, specify the y-intercept with \code{intercept}
+#' and the slope with \code{slope}.
 #'
-#' @seealso \code{\link{geom_vline}} for vertical lines, 
-#'  \code{\link{geom_abline}} for lines defined by a slope and intercept,
-#'  \code{\link{geom_segment}} for a more general approach
-#' @export
-#' @inheritParams geom_point
 #' @param show_guide should a legend be drawn? (defaults to \code{FALSE})
+#' @inheritParams geom_point
+#' @seealso
+#'  \code{\link{annotate}} for adding annotations.
+#' @export
 #' @examples
-#' p <- ggplot(mtcars, aes(x = wt, y=mpg)) + geom_point()
+#' p <- ggplot(mtcars, aes(x = wt, y = mpg)) + geom_point()
 #' 
-#' p + geom_hline(aes(yintercept=mpg))
-#' p + geom_hline(yintercept=20)
-#' p + geom_hline(yintercept=seq(10, 30, by=5))
+#' # Individual lines
+#' p + annotate("hline", yintercept = 20)
+#' p + annotate("vline", xintercept = 5, colour = "blue")
+#' p + annotate("abline", intercept = 20, slope = 1)
+#'
+#' # Using vectors to specify lines
+#' p + annotate("hline", yintercept = seq(10, 30, by = 5))
+#' p + annotate("vline", xintercept = 1:5, colour="darkgreen", linetype = "longdash")
+#' p + annotate("abline", intercept = c(17, 22), slope = c(0.5, 1))
 #' 
+#' # Map a variable to line properties
+#' p + geom_hline(aes(yintercept = mpg))
+#' p + geom_vline(aes(xintercept = wt), colour = "blue")
+#' p + geom_abline(aes(intercept = mpg, slope = wt))
+#'
+#' # Calculate slope and intercept of line of best fit
+#' coef(lm(mpg ~ wt, data = mtcars))
+#' p + annotate_abline(intercept = 37, slope = -5)
+#'
 #' # With coordinate transforms
-#' p + geom_hline(aes(yintercept=mpg)) + coord_equal()
-#' p + geom_hline(aes(yintercept=mpg)) + coord_flip()
-#' p + geom_hline(aes(yintercept=mpg)) + coord_polar()
+#' p + geom_hline(aes(yintercept = mpg)) + coord_equal()
+#' p + geom_hline(aes(yintercept = mpg)) + coord_flip()
+#' p + geom_hline(aes(yintercept = mpg)) + coord_polar()
 #' 
 #' # To display different lines in different facets, you need to 
 #' # create a data frame.
 #' p <- qplot(mpg, wt, data=mtcars, facets = vs ~ am)
 #' 
 #' hline.data <- data.frame(z = 1:4, vs = c(0,0,1,1), am = c(0,1,0,1))
-#' p + geom_hline(aes(yintercept = z), hline.data)
-geom_hline <- function (mapping = NULL, data = NULL, stat = "hline", position = "identity", show_guide = FALSE, ...) { 
+#' p + geom_hline(aes(yintercept = z), hline.data, inherit.aes = FALSE)
+geom_hline <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity", show_guide = FALSE, ...) { 
   GeomHline$new(mapping = mapping, data = data, stat = stat, position = position, show_guide = show_guide, ...)
 }
 
 GeomHline <- proto(Geom, {
   objname <- "hline"
 
-  new <- function(., data = NULL, mapping = NULL, yintercept = NULL, ...) {
-    if (is.numeric(yintercept)) {
-      data <- data.frame(yintercept = yintercept)
-      yintercept <- NULL
-      mapping <- aes_all(names(data))
-    }
-    .super$new(., data = data, mapping = mapping, inherit.aes = FALSE, 
-      yintercept = yintercept, ...)
-  }
-
-  draw <- function(., data, scales, coordinates, ...) {
+  draw <- function(., data, scales, coordinates, yintercept = NULL, ...) {
     ranges <- coord_range(coordinates, scales)
 
+    data$y    <- yintercept %||% data$yintercept
+    data$yend <- data$y
     data$x    <- ranges$x[1]
     data$xend <- ranges$x[2]
 
-    GeomSegment$draw(unique(data), scales, coordinates)
+    if(nrow(data) > 1 && nrow(unique(data)) == 1)
+      message(nrow(data), " identical hlines were drawn. If you want just one line, use annontate(\"hline\") instead of geom_hline().")
+
+    GeomSegment$draw(data, scales, coordinates)
   }
 
   icon <- function(.) linesGrob(c(0, 1), c(0.5, 0.5))

R/geom-vline.r

@@ -1,67 +1,24 @@
-#' Line, vertical.
-#' 
-#' This geom allows you to annotate the plot with vertical lines (see
-#' \code{\link{geom_hline}} and \code{\link{geom_abline}} for other types of
-#' lines.
-#'
-#' There are two ways to use it.  You can either specify the intercept of the
-#' line in the call to the geom, in which case the line will be in the same
-#' position in every panel.  Alternatively, you can supply a different
-#' intercept for each panel using a data.frame.  See the examples for the
-#' differences.
-#'
-#' @param show_guide should a legend be drawn? (defaults to \code{FALSE})
-#' @inheritParams geom_point
-#' @seealso
-#'  \code{\link{geom_hline}} for horizontal lines,
-#'  \code{\link{geom_abline}} for lines defined by a slope and intercept,
-#'  \code{\link{geom_segment}} for a more general approach"
+#' @rdname geom_hline
 #' @export
-#' @examples
-#' # Fixed lines
-#' p <- ggplot(mtcars, aes(x = wt, y = mpg)) + geom_point()
-#' p + geom_vline(xintercept = 5)
-#' p + geom_vline(xintercept = 1:5)
-#' p + geom_vline(xintercept = 1:5, colour="green", linetype = "longdash")
-#' p + geom_vline(aes(xintercept = wt))
-#' 
-#' # With coordinate transforms
-#' p + geom_vline(aes(xintercept = wt)) + coord_equal()
-#' p + geom_vline(aes(xintercept = wt)) + coord_flip()
-#' p + geom_vline(aes(xintercept = wt)) + coord_polar()
-#' 
-#' p2 <- p + aes(colour = factor(cyl))
-#' p2 + geom_vline(xintercept = 15)
-#'
-#' # To display different lines in different facets, you need to 
-#' # create a data frame.
-#' p <- qplot(mpg, wt, data=mtcars, facets = vs ~ am)   
-#' vline.data <- data.frame(z = c(15, 20, 25, 30), vs = c(0, 0, 1, 1), am = c(0, 1, 0, 1)) 
-#' p + geom_vline(aes(xintercept = z), vline.data)
-geom_vline <- function (mapping = NULL, data = NULL, stat = "vline", position = "identity", show_guide = FALSE, ...) { 
+geom_vline <- function (mapping = NULL, data = NULL, stat = "identity", position = "identity", show_guide = FALSE, ...) { 
   GeomVline$new(mapping = mapping, data = data, stat = stat, position = position, show_guide = show_guide, ...)
 }
 
 GeomVline <- proto(Geom, {
   objname <- "vline"
 
-  new <- function(., data = NULL, mapping = NULL, xintercept = NULL, ...) {
-    if (is.numeric(xintercept)) {
-      data <- data.frame(xintercept = xintercept)
-      xintercept <- NULL
-      mapping <- aes_all(names(data))
-    }
-    .super$new(., data = data, mapping = mapping, inherit.aes = FALSE, 
-      xintercept = xintercept, ...)
-  }
-
-  draw <- function(., data, scales, coordinates, ...) {
+  draw <- function(., data, scales, coordinates, xintercept = NULL, ...) {
     ranges <- coord_range(coordinates, scales)
 
+    data$x    <- xintercept %||% data$xintercept
+    data$xend <- data$x
     data$y    <- ranges$y[1]
     data$yend <- ranges$y[2]
 
-    GeomSegment$draw(unique(data), scales, coordinates)
+    if(nrow(data) > 1 && nrow(unique(data)) == 1)
+      message(nrow(data), " identical vlines were drawn. If you want just one line, use annontate(\"vline\") instead of geom_vline().")
+
+    GeomSegment$draw(data, scales, coordinates)
   }