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\encoding{UTF-8}
\name{ggroc.roc}
\alias{ggroc.roc}
\alias{ggroc.smooth.roc}
\alias{ggroc.list}
\alias{ggroc}
\title{
Plot a ROC curve with ggplot2
}
\description{
This function plots a ROC curve with ggplot2.
}
\usage{
\S3method{ggroc}{roc}(data, legacy.axes = FALSE, ...)
\S3method{ggroc}{smooth.roc}(data, legacy.axes = FALSE, ...)
\S3method{ggroc}{list}(data, aes = c("colour", "alpha", "linetype", "linewidth", "size", "group"),
legacy.axes = FALSE, ...)
}
\arguments{
\item{data}{a roc object from the \link{roc} function, or a list of roc objects.
}
\item{aes}{the name(s) of the aesthetics for \code{\link[ggplot2:geom_path]{geom_line}}
to map to the different ROC curves supplied.
}
\item{legacy.axes}{a logical indicating if the specificity axis (x
axis) must be plotted as as decreasing \dQuote{specificity}
(\code{FALSE}, the default) or increasing \dQuote{1 - specificity}
(\code{TRUE}) as in most legacy software.
}
\item{...}{additional aesthetics for \code{\link[ggplot2:geom_path]{geom_line}}
to set: \code{alpha}, \code{colour}, \code{linetype}, \code{linewidth}
(new in ggplot2 3.4.0), and \code{size} (before ggplot2 3.4.0).
The \code{group} aesthetic is always active since version 1.18.5 and is
kept for backwards compatibility.
}
}
\details{
This function initializes a ggplot object from a ROC curve (or multiple if a list is passed). It returns the ggplot with a line layer on it. You can print it directly or add your own layers and theme elements.
}
\seealso{
\code{\link{roc}}, \code{\link{plot.roc}}, \pkg{\link[ggplot2:ggplot2-package]{ggplot2}}
}
\examples{
# Create a basic roc object
data(aSAH)
rocobj <- roc(aSAH$outcome, aSAH$s100b)
rocobj2 <- roc(aSAH$outcome, aSAH$wfns)
if (require(ggplot2)) {
g <- ggroc(rocobj)
g
# with additional aesthetics:
ggroc(rocobj, alpha = 0.5, colour = "red", linetype = 2, size = 2)
# You can then your own theme, etc.
g + theme_minimal() + ggtitle("My ROC curve") +
geom_segment(aes(x = 1, xend = 0, y = 0, yend = 1), color="grey", linetype="dashed")
# And change axis labels to FPR/FPR
gl <- ggroc(rocobj, legacy.axes = TRUE)
gl
gl + xlab("FPR") + ylab("TPR") +
geom_segment(aes(x = 0, xend = 1, y = 0, yend = 1), color="darkgrey", linetype="dashed")
# Multiple curves:
g2 <- ggroc(list(s100b=rocobj, wfns=rocobj2, ndka=roc(aSAH$outcome, aSAH$ndka)))
g2
# This is equivalent to using roc.formula:
roc.list <- roc(outcome ~ s100b + ndka + wfns, data = aSAH)
g.list <- ggroc(roc.list)
g.list
# You can change the aesthetics as you normally would with ggplot2:
g.list + scale_colour_brewer(palette="RdGy")
g.list + scale_colour_manual(values = c("red", "blue", "black"))
# with additional aesthetics:
g3 <- ggroc(roc.list, linetype=2)
g3
g4 <- ggroc(roc.list, aes="linetype", color="red")
g4
# changing multiple aesthetics:
g5 <- ggroc(roc.list, aes=c("linetype", "color"))
g5
# OR faceting
g.list + facet_grid(.~name) + theme(legend.position="none")
}
}
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