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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/coord-transform.R
\name{coord_trans}
\alias{coord_trans}
\title{Transformed Cartesian coordinate system}
\usage{
coord_trans(
x = "identity",
y = "identity",
xlim = NULL,
ylim = NULL,
limx = deprecated(),
limy = deprecated(),
clip = "on",
expand = TRUE
)
}
\arguments{
\item{x, y}{Transformers for x and y axes or their names.}
\item{xlim, ylim}{Limits for the x and y axes.}
\item{limx, limy}{\ifelse{html}{\href{https://lifecycle.r-lib.org/articles/stages.html#deprecated}{\figure{lifecycle-deprecated.svg}{options: alt='[Deprecated]'}}}{\strong{[Deprecated]}} use \code{xlim} and \code{ylim} instead.}
\item{clip}{Should drawing be clipped to the extent of the plot panel? A
setting of \code{"on"} (the default) means yes, and a setting of \code{"off"}
means no. In most cases, the default of \code{"on"} should not be changed,
as setting \code{clip = "off"} can cause unexpected results. It allows
drawing of data points anywhere on the plot, including in the plot margins. If
limits are set via \code{xlim} and \code{ylim} and some data points fall outside those
limits, then those data points may show up in places such as the axes, the
legend, the plot title, or the plot margins.}
\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{
\code{coord_trans()} is different to scale transformations in that it occurs after
statistical transformation and will affect the visual appearance of geoms - there is
no guarantee that straight lines will continue to be straight.
}
\details{
Transformations only work with continuous values: see
\code{\link[scales:new_transform]{scales::new_transform()}} for list of transformations, and instructions
on how to create your own.
}
\examples{
\donttest{
# See ?geom_boxplot for other examples
# Three ways of doing transformation in ggplot:
# * by transforming the data
ggplot(diamonds, aes(log10(carat), log10(price))) +
geom_point()
# * by transforming the scales
ggplot(diamonds, aes(carat, price)) +
geom_point() +
scale_x_log10() +
scale_y_log10()
# * by transforming the coordinate system:
ggplot(diamonds, aes(carat, price)) +
geom_point() +
coord_trans(x = "log10", y = "log10")
# The difference between transforming the scales and
# transforming the coordinate system is that scale
# transformation occurs BEFORE statistics, and coordinate
# transformation afterwards. Coordinate transformation also
# changes the shape of geoms:
d <- subset(diamonds, carat > 0.5)
ggplot(d, aes(carat, price)) +
geom_point() +
geom_smooth(method = "lm") +
scale_x_log10() +
scale_y_log10()
ggplot(d, aes(carat, price)) +
geom_point() +
geom_smooth(method = "lm") +
coord_trans(x = "log10", y = "log10")
# Here I used a subset of diamonds so that the smoothed line didn't
# drop below zero, which obviously causes problems on the log-transformed
# scale
# With a combination of scale and coordinate transformation, it's
# possible to do back-transformations:
ggplot(diamonds, aes(carat, price)) +
geom_point() +
geom_smooth(method = "lm") +
scale_x_log10() +
scale_y_log10() +
coord_trans(x = scales::transform_exp(10), y = scales::transform_exp(10))
# cf.
ggplot(diamonds, aes(carat, price)) +
geom_point() +
geom_smooth(method = "lm")
# Also works with discrete scales
set.seed(1)
df <- data.frame(a = abs(rnorm(26)),letters)
plot <- ggplot(df,aes(a,letters)) + geom_point()
plot + coord_trans(x = "log10")
plot + coord_trans(x = "sqrt")
}
}
\seealso{
The \href{https://ggplot2-book.org/coord#transformations-with-coord_trans}{coord transformations section} of the online ggplot2 book.
}
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