Improve interaction of geom_vline/geom_hline with coord_flip by imple…

…menting non-finite positions

NEWS

@@ -45,4 +45,7 @@ ggplot2 0.8.5 (2009-XX-XX) ----------------------------------------
 * coord_trans now respects scale expand parameter (expansion occurs after 
   tranformation) (Fixes #14)
 * coord_cartesian now correctly sets limits when one or both of the position
-  scales are non-linear.  (Fixes #17)
+  scales are non-linear.  (Fixes #17)
+* x and y position can be set to Inf or -Inf to refer to the top/right and 
+  bottom/left extents of the panel (implements #18)
+* geom_hline and geom_vline now work with coord_flip (fixes #30)

R/coord-.r

@@ -7,7 +7,7 @@ Coord <- proto(TopLevel, expr={
   # Rescaling at coord level should not be clipped: this is what 
   # makes zooming work
   rescale_var <- function(., data, range, clip = FALSE) {
-    rescale(data, 0:1, range, clip = clip)  
+    rescale(data, 0:1, range, clip = clip)
   }
 
   munch <- function(., data, details, npieces=50) {

R/coord-cartesian-.r

@@ -7,7 +7,8 @@ CoordCartesian <- proto(Coord, expr={
     rescale_x <- function(data) .$rescale_var(data, details$x.range)
     rescale_y <- function(data) .$rescale_var(data, details$y.range)
 
-    transform_position(data, rescale_x, rescale_y)
+    data <- transform_position(data, rescale_x, rescale_y)
+    transform_position(data, trim_infinite_01, trim_infinite_01)
   }
 
   compute_ranges <- function(., scales) {

R/coord-cartesian-flipped.r

@@ -5,6 +5,8 @@ CoordFlip <- proto(CoordCartesian, expr={
     rescale_y <- function(data) .$rescale_var(data, details$y.range)
 
     data <- transform_position(data, rescale_y, rescale_x)
+    data <- transform_position(data, trim_infinite_01, trim_infinite_01)
+
     rename(data, c(
       x = "y",       y = "x", 
       xend = "yend", yend = "xend", 

R/coord-polar.r

@@ -69,7 +69,7 @@ CoordPolar <- proto(Coord, {
   transform <- function(., data, details) {
     data <- .$rename_data(data)
 
-    within(data, {
+    data <- within(data, {
       r <- .$r_rescale(r, details)
       theta <- .$theta_rescale(theta, details)
 

R/coord-transform.r

@@ -12,7 +12,8 @@ CoordTrans <- proto(CoordCartesian, expr={
     trans_x <- function(data) .$transform_x(data, details$x.range)
     trans_y <- function(data) .$transform_y(data, details$y.range)
 
-    transform_position(data, trans_x, trans_y)
+    data <- transform_position(data, trans_x, trans_y)
+    transform_position(data, trim_infinite_01, trim_infinite_01)
   }
   transform_x <- function(., data, range) {
     rescale(.$xtr$transform(data), 0:1, range, clip = FALSE)

R/geom-hline.r

@@ -9,8 +9,8 @@ GeomHline <- proto(Geom, {
   }
 
   draw <- function(., data, scales, coordinates, ...) {
-    data$x    <- scales$x.range[1]
-    data$xend <- scales$x.range[2]    
+    data$x    <- -Inf
+    data$xend <- Inf
 
     GeomSegment$draw(unique(data), scales, coordinates)
   }

R/geom-segment.r

@@ -1,6 +1,7 @@
 GeomSegment <- proto(Geom, {
   draw <- function(., data, scales, coordinates, arrow=NULL, ...) {
     if (!coordinates$muncher()) {
+      browser()
       return(with(coordinates$transform(data, scales), 
         segmentsGrob(x, y, xend, yend, default.units="native",
         gp = gpar(col=alpha(colour, alpha), lwd=size * .pt, 

R/geom-vline.r

@@ -9,8 +9,8 @@ GeomVline <- proto(Geom, {
   }
 
   draw <- function(., data, scales, coordinates, ...) {
-    data$y    <- scales$y.range[1]
-    data$yend <- scales$y.range[2]    
+    data$y    <- -Inf
+    data$yend <- Inf
 
     GeomSegment$draw(unique(data), scales, coordinates)
   }

R/scale-continuous-.r

@@ -61,7 +61,8 @@ ScaleContinuous <- proto(Scale, funEnvir = globalenv(), {
   # By default, a continuous scale does no transformation in the mapping stage
   # See scale_size for an exception
   map <- function(., values) {
-    as.numeric(ifelse(values %inside% .$output_set(), values, NA))
+    trunc <- !is.finite(values) | values %inside% .$output_set()
+    as.numeric(ifelse(trunc, values, NA))
   }
 
   # By default, the range of a continuous scale is the same as its

R/utilities-position.r

@@ -11,4 +11,20 @@ expand_range <- function(range, mul = 0, add = 0, zero = 0.5) {
   } else {    
     range + c(-1, 1) * (diff(range) * mul + add)
   }
-}
+}
+
+# Trim non-finite numbers to specified range
+# 
+# @keywords internal
+# @alias trim_infinite_01
+trim_infinite <- function(x, range) {
+  x[x == -Inf] <- range[1]
+  x[x == Inf] <- range[2]
+  x
+}
+
+trim_infinite_01 <- function(x) {
+  trim_infinite(x, c(0, 1))
+}
+
+

R/utilities.r

@@ -136,8 +136,13 @@ rescale <- function(x, to=c(0,1), from=range(x, na.rm=TRUE), clip = TRUE) {
     warning("Categorical variable automatically converted to continuous", call.=FALSE)
     x <- as.numeric(x)
   }
-  scaled <- (x-from[1])/diff(from)*diff(to) + to[1]
-  if (clip) ifelse(scaled %inside% to, scaled, NA) else scaled
+  scaled <- (x - from[1]) / diff(from) * diff(to) + to[1]
+
+  if (clip) {
+    ifelse(!is.finite(scaled) | scaled %inside% to, scaled, NA) 
+  } else {
+    scaled
+  }
 }