facet_wrap.Rd

\name{facet_wrap}
\alias{facet_wrap}
\title{Wrap a 1d ribbon of panels into 2d.}
\usage{
  facet_wrap(facets, nrow = NULL, ncol = NULL,
    scales = "fixed", shrink = TRUE, as.table = TRUE)
}
\arguments{
  \item{nrow}{number of rows}

  \item{ncol}{number of columns}

  \item{facet}{formula specifying variables to facet by}

  \item{scales}{should scales be fixed, free, or free in
  one dimension (\code{free_x}, \code{free_y})}
}
\description{
  Wrap a 1d ribbon of panels into 2d.
}
\examples{
d <- ggplot(diamonds, aes(carat, price, fill = ..density..)) +
  xlim(0, 2) + stat_binhex(na.rm = TRUE) + opts(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) + opts(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 = F)

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