Wrap a 1d ribbon of panels into 2d.

Usage

facet_wrap(facets, nrow = NULL, ncol = NULL, scales = "fixed", shrink = TRUE, as.table = TRUE, 
  drop = TRUE)

Arguments

nrow

number of rows

ncol

number of columns

facets

formula specifying variables to facet by

scales

should scales be fixed ("fixed", the default), free ("free"), or free in one dimension ("free_x", "free_y")

shrink

If TRUE, will shrink scales to fit output of statistics, not raw data. If FALSE, will be range of raw data before statistical summary.

as.table

If TRUE, the default, the facets are laid out like a table with highest values at the bottom-right. If FALSE, the facets are laid out like a plot with the highest value at the top-right.

drop

If TRUE, the default, all factor levels not used in the data will automatically be dropped. If FALSE, all factor levels will be shown, regardless of whether or not they appear in the data.

Examples

d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
  xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1)
d + facet_wrap(~ color)


d + facet_wrap(~ color, ncol = 1)


d + facet_wrap(~ color, ncol = 4)


d + facet_wrap(~ color, nrow = 1)


d + facet_wrap(~ color, nrow = 3)



# Using multiple variables continues to wrap the long ribbon of
# plots into 2d - the ribbon just gets longer
# d + facet_wrap(~ color + cut)

# To change plot order of facet wrap,
# change the order of varible levels with factor()
diamonds$color <- factor(diamonds$color, levels = c("G", "J", "D", "E", "I", "F", "H"))
# Repeat first example with new order
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
xlim(0, 2) + stat_binhex(na.rm = TRUE) + theme(aspect.ratio = 1)
d + facet_wrap(~ color)



# You can choose to keep the scales constant across all panels
# or vary the x scale, the y scale or both:
p <- qplot(price, data = diamonds, geom = "histogram", binwidth = 1000)
p + facet_wrap(~ color)


p + facet_wrap(~ color, scales = "free_y")



p <- qplot(displ, hwy, data = mpg)
p + facet_wrap(~ cyl)


p + facet_wrap(~ cyl, scales = "free")



# Use as.table to to control direction of horizontal facets, TRUE by default
p + facet_wrap(~ cyl, as.table = FALSE)



# Add data that does not contain all levels of the faceting variables
cyl6 <- subset(mpg, cyl == 6)
p + geom_point(data = cyl6, colour = "red", size = 1) +
  facet_wrap(~ cyl)

Warning message:
invalid factor level, NAs generated

p + geom_point(data = transform(cyl6, cyl = 7), colour = "red") +
  facet_wrap(~ cyl)

Warning message:
invalid factor level, NAs generated
Warning message:
invalid factor level, NAs generated

p + geom_point(data = transform(cyl6, cyl = NULL), colour = "red") +
  facet_wrap(~ cyl)