pROC (version 1.13.0)

ggroc.roc: Plot a ROC curve with ggplot2

Description

This function plots a ROC curve with ggplot2.

Usage

# S3 method for roc
ggroc(data, legacy.axes = FALSE, ...)
# S3 method for list
ggroc(data, aes = c("colour", "alpha", "linetype", "size", "group"),
      legacy.axes = FALSE, ...)

Arguments

data

a roc object from the roc function, or a list of roc objects.

aes

the name of the aesthetics for geom_line to map to the different ROC curves supplied. Use “group” if you want the curves to appear with the same aestetic, for instance if you are faceting instead.

legacy.axes

a logical indicating if the specificity axis (x axis) must be plotted as as decreasing “specificity” (FALSE, the default) or increasing “1 - specificity” (TRUE) as in most legacy software.

...

additional aesthetics for geom_line to set: alpha, colour, linetype and size.

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.

This function is experimental and may change in the future. Please report bugs and feedback on the GitHub issue tracker.

See Also

roc, plot.roc, ggplot2

Examples

# NOT RUN {
# Create a basic roc object
data(aSAH)
rocobj <- roc(aSAH$outcome, aSAH$s100b)
rocobj2 <- roc(aSAH$outcome, aSAH$wfns)

library(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")

# 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

# with additional aesthetics:
g3 <- ggroc(roc.list, linetype=2)
g3
g4 <- ggroc(roc.list, aes="linetype", color="red")
g4

# OR faceting
g.list + facet_grid(.~name) + theme(legend.position="none")
# To have all the curves of the same color, use aes="group":
g.group <- ggroc(roc.list, aes="group")
g.group
g.group + facet_grid(.~name)

# }