Speed up facet_grid examples

Author: hadley

R/facet-grid-.r

@@ -45,119 +45,69 @@
 #'   will be shown, regardless of whether or not they appear in the data.
 #' @export
 #' @examples
-#' \donttest{
-#' p <- ggplot(mtcars, aes(mpg, wt)) + geom_point()
-#' # With one variable
-#' p + facet_grid(. ~ cyl)
-#' p + facet_grid(cyl ~ .)
+#' p <- ggplot(mpg, aes(displ, cty)) + geom_point()
 #'
-#' # With two variables
-#' p + facet_grid(vs ~ am)
-#' p + facet_grid(am ~ vs)
-#' p + facet_grid(vs ~ am, margins=TRUE)
+#' p + facet_grid(. ~ cyl)
+#' p + facet_grid(drv ~ .)
+#' p + facet_grid(drv ~ cyl)
 #'
 #' # To change plot order of facet grid,
 #' # change the order of variable levels with factor()
 #'
-#' set.seed(6809)
-#' diamonds <- diamonds[sample(nrow(diamonds), 1000), ]
-#' diamonds$cut <- factor(diamonds$cut,
-#'          levels = c("Ideal", "Very Good", "Fair", "Good", "Premium"))
-#'
-#' # Repeat first example with new order
-#' p <- ggplot(diamonds, aes(carat, ..density..)) +
-#'         geom_histogram(binwidth = 1)
-#' p + facet_grid(. ~ cut)
-#'
-#' g <- ggplot(mtcars, aes(mpg, wt)) +
-#'   geom_point()
-#' g + facet_grid(. ~ vs + am)
-#' g + facet_grid(vs + am ~ .)
-#'
-#' # You can also use strings, which makes it a little easier
-#' # when writing functions that generate faceting specifications
-#'
-#' p + facet_grid("cut ~ .")
-#'
-#' # see also ?plotmatrix for the scatterplot matrix
-#'
-#' # If there isn't any data for a given combination, that panel
-#' # will be empty
-#'
-#' g + facet_grid(cyl ~ vs)
-#'
 #' # If you combine a facetted dataset with a dataset that lacks those
 #' # facetting variables, the data will be repeated across the missing
 #' # combinations:
-#'
-#' g + facet_grid(vs ~ cyl)
-#'
-#' df <- data.frame(mpg = 22, wt = 3)
-#' g + facet_grid(vs ~ cyl) +
+#' df <- data.frame(displ = mean(mpg$displ), cty = mean(mpg$cty))
+#' p +
+#'   facet_grid(. ~ cyl) +
 #'   geom_point(data = df, colour = "red", size = 2)
 #'
-#' df2 <- data.frame(mpg = c(19, 22), wt = c(2,4), vs = c(0, 1))
-#' g + facet_grid(vs ~ cyl) +
-#'   geom_point(data = df2, colour = "red", size = 2)
-#'
-#' df3 <- data.frame(mpg = c(19, 22), wt = c(2,4), vs = c(1, 1))
-#' g + facet_grid(vs ~ cyl) +
-#'   geom_point(data = df3, colour = "red", size = 2)
-#'
-#'
+#' # Free scales -------------------------------------------------------
 #' # You can also choose whether the scales should be constant
 #' # across all panels (the default), or whether they should be allowed
 #' # to vary
 #' mt <- ggplot(mtcars, aes(mpg, wt, colour = factor(cyl))) +
 #'   geom_point()
 #'
 #' mt + facet_grid(. ~ cyl, scales = "free")
+#'
 #' # If scales and space are free, then the mapping between position
-#' # and values in the data will be the same across all panels
-#' mt + facet_grid(. ~ cyl, scales = "free", space = "free")
+#' # and values in the data will be the same across all panels. This
+#' # is particularly useful for categorical axes
+#' ggplot(mpg, aes(drv, model)) +
+#'   geom_point() +
+#'   facet_grid(manufacturer ~ ., scales = "free", space = "free") +
+#'   theme(strip.text.y = element_text(angle = 0))
 #'
-#' mt + facet_grid(vs ~ am, scales = "free")
-#' mt + facet_grid(vs ~ am, scales = "free_x")
-#' mt + facet_grid(vs ~ am, scales = "free_y")
-#' mt + facet_grid(vs ~ am, scales = "free", space = "free")
-#' mt + facet_grid(vs ~ am, scales = "free", space = "free_x")
-#' mt + facet_grid(vs ~ am, scales = "free", space = "free_y")
+#' # Facet labels ------------------------------------------------------
+#' p <- ggplot(mtcars, aes(wt, mpg)) + geom_point()
+#' p
 #'
-#' # You may need to set your own breaks for consistent display:
-#' mt + facet_grid(. ~ cyl, scales = "free_x", space = "free") +
-#'   scale_x_continuous(breaks = seq(10, 36, by = 2))
-#' # Adding scale limits override free scales:
-#' last_plot() + xlim(10, 15)
+#' # label_both() displays both variable name and value
+#' p + facet_grid(vs ~ cyl, labeller = label_both)
 #'
-#' # Free scales are particularly useful for categorical variables
-#' ggplot(mpg, aes(cty, model)) +
+#' # label_parsed() parses text into mathematical expressions, see ?plotmath
+#' mtcars$cyl2 <- factor(mtcars$cyl, labels = c("alpha", "beta", "sqrt(x, y)"))
+#' ggplot(mtcars, aes(wt, mpg)) +
 #'   geom_point() +
-#'   facet_grid(manufacturer ~ ., scales = "free", space = "free")
-#' # particularly when you reorder factor levels
-#' mpg$model <- reorder(mpg$model, mpg$cty)
-#' manufacturer <- reorder(mpg$manufacturer, mpg$cty)
-#' last_plot() %+% mpg + theme(strip.text.y = element_text())
+#'   facet_grid(. ~ cyl2, labeller = label_parsed)
 #'
-#' # Use as.table to to control direction of horizontal facets, TRUE by default
-#' h <- ggplot(mtcars, aes(x = mpg, y = wt)) +
-#'   geom_point()
-#' h + facet_grid(cyl ~ vs)
-#' h + facet_grid(cyl ~ vs, as.table = FALSE)
+#' # label_bquote() makes it easy to construct math expressions
+#' p + facet_grid(. ~ vs, labeller = label_bquote(cols = alpha ^ .(vs)))
 #'
-#' # Use labeller to control facet labels, label_value is default
-#' h + facet_grid(cyl ~ vs, labeller = label_both)
-#' # Using label_parsed, see ?plotmath for more options
-#' mtcars$cyl2 <- factor(mtcars$cyl, labels = c("alpha", "beta", "sqrt(x, y)"))
-#' k <- ggplot(mtcars, aes(wt, mpg)) +
-#'   geom_point()
-#' k + facet_grid(. ~ cyl2)
-#' k + facet_grid(. ~ cyl2, labeller = label_parsed)
-#' # For label_bquote the label value is x.
-#' p <- ggplot(mtcars, aes(wt, mpg)) +
-#'   geom_point()
-#' p + facet_grid(. ~ vs, labeller = label_bquote(alpha ^ .(x)))
-#' p + facet_grid(. ~ vs, labeller = label_bquote(.(x) ^ .(x)))
+#' # The facet strips can be displayed near the axes with switch
+#' data <- transform(mtcars,
+#'   am = factor(am, levels = 0:1, c("Automatic", "Manual")),
+#'   gear = factor(gear, levels = 3:5, labels = c("Three", "Four", "Five"))
+#' )
+#' p <- ggplot(data, aes(mpg, disp)) + geom_point()
+#' p + facet_grid(am ~ gear, switch = "both")
+#' # It looks better without boxes around the strips
+#' p + facet_grid(am ~ gear, switch = "both") +
+#'   theme(strip.background = element_blank())
 #'
+#' # Margins ----------------------------------------------------------
+#' \dontrun{
 #' # Margins can be specified by logically (all yes or all no) or by specific
 #' # variables as (character) variable names
 #' mg <- ggplot(mtcars, aes(x = mpg, y = wt)) + geom_point()
@@ -170,20 +120,6 @@
 #' mg + facet_grid(vs + am ~ gear, margins = "vs")
 #' mg + facet_grid(vs + am ~ gear, margins = "gear")
 #' mg + facet_grid(vs + am ~ gear, margins = c("gear", "am"))
-#'
-#' # The facet strips can be displayed near the axes with switch
-#' data <- transform(mtcars,
-#'   am = factor(am, levels = 0:1, c("Automatic", "Manual")),
-#'   gear = factor(gear, levels = 3:5, labels = c("Three", "Four", "Five"))
-#' )
-#' p <- ggplot(data, aes(mpg, disp)) + geom_point()
-#' p + facet_grid(am ~ gear, switch = "both") + theme_light()
-#'
-#' # It may be more aesthetic to use a theme without boxes around
-#' # around the strips.
-#' p + facet_grid(am ~ gear + vs, switch = "y") + theme_minimal()
-#' p + facet_grid(am ~ ., switch = "y") +
-#'   theme_gray() %+replace% theme(strip.background  = element_blank())
 #' }
 #' @importFrom plyr as.quoted
 facet_grid <- function(facets, margins = FALSE, scales = "fixed", space = "fixed", shrink = TRUE, labeller = "label_value", as.table = TRUE, switch = NULL, drop = TRUE) {