coord_cartesian.Rd

% Generated by roxygen2 (4.1.1): do not edit by hand
% Please edit documentation in R/coord-cartesian-.r
\name{coord_cartesian}
\alias{coord_cartesian}
\title{Cartesian coordinates.}
\usage{
coord_cartesian(xlim = NULL, ylim = NULL, expand = TRUE)
}
\arguments{
\item{xlim,ylim}{Limits for the x and y axes.}

\item{expand}{If \code{TRUE}, the default, adds a small expansion factor to
the limits to ensure that data and axes don't overlap. If \code{FALSE},
limits are taken exactly from the data or \code{xlim}/\code{ylim}.}
}
\description{
The Cartesian coordinate system is the most familiar, and common, type of
coordinate system. Setting limits on the coordinate system will zoom the
plot (like you're looking at it with a magnifying glass), and will not
change the underlying data like setting limits on a scale will.
}
\examples{
# There are two ways of zooming the plot display: with scales or
# with coordinate systems.  They work in two rather different ways.

p <- ggplot(mtcars, aes(disp, wt)) +
  geom_point() +
  geom_smooth()
p

# Setting the limits on a scale converts all values outside the range to NA.
p + scale_x_continuous(limits = c(325, 500))

# Setting the limits on the coordinate system performs a visual zoom.
# The data is unchanged, and we just view a small portion of the original
# plot. Note how smooth continues past the points visible on this plot.
p + coord_cartesian(xlim = c(325, 500))

# By default, the same expansion factor is applied as when setting scale
# limits. You can set the limits precisely by setting expand = FALSE
p + coord_cartesian(xlim = c(325, 500), expand = FALSE)

# Simiarly, we can use expand = FALSE to turn off expansion with the
# default limits
p + coord_cartesian(expand = FALSE)

# You can see the same thing with this 2d histogram
d <- ggplot(diamonds, aes(carat, price)) +
  stat_bin2d(bins = 25, colour = "white")
d

# When zooming the scale, the we get 25 new bins that are the same
# size on the plot, but represent smaller regions of the data space
d + scale_x_continuous(limits = c(0, 1))

# When zooming the coordinate system, we see a subset of original 50 bins,
# displayed bigger
d + coord_cartesian(xlim = c(0, 1))
}