geom_vline.Rd

% Generated by roxygen2 (4.1.0): do not edit by hand
% Please edit documentation in R/geom-vline.r
\name{geom_vline}
\alias{geom_vline}
\title{Line, vertical.}
\usage{
geom_vline(mapping = NULL, data = NULL, stat = "vline",
  position = "identity", show_guide = FALSE, ...)
}
\arguments{
\item{mapping}{The aesthetic mapping, usually constructed with
\code{\link{aes}} or \code{\link{aes_string}}. Only needs to be set
at the layer level if you are overriding the plot defaults.}

\item{data}{A layer specific dataset - only needed if you want to override
the plot defaults.}

\item{stat}{The statistical transformation to use on the data for this
layer.}

\item{position}{The position adjustment to use for overlapping points
on this layer}

\item{show_guide}{should a legend be drawn? (defaults to \code{FALSE})}

\item{...}{other arguments passed on to \code{\link{layer}}. This can
include aesthetics whose values you want to set, not map. See
\code{\link{layer}} for more details.}
}
\description{
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.
}
\details{
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.
}
\section{Aesthetics}{

\Sexpr[results=rd,stage=build]{ggplot2:::rd_aesthetics("geom", "vline")}
}
\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)
}
\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"
}