R Graphical Manual

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Last data update: 2014.03.03

R: Add a ROC line to a ROC plot

lines.roc

R Documentation

Add a ROC line to a ROC plot

Description

This convenience function adds a ROC line to a ROC curve.

Usage

## S3 method for class 'roc'
lines(x, ...)
## S3 method for class 'smooth.roc'
lines(x, ...)
## S3 method for class 'roc'
lines.roc(x, lwd=2, ...)
## S3 method for class 'formula'
lines.roc(x, data, ...)
## Default S3 method:
lines.roc(x, predictor, ...)
## S3 method for class 'smooth.roc'
lines.roc(x, ...)

Arguments

`x`	a roc object from the roc function (for plot.roc.roc), a formula (for plot.roc.formula) or a response vector (for plot.roc.default).
`predictor, data`	arguments for the roc function.
`lwd`	line width (see `par`).
`...`	graphical parameters for `lines`, and especially `type` (see `plot.default`) and arguments for `par` such as `col` (color), `lty` (line type) or line characteristics `lend`, `ljoin` and `lmitre`.

Value

This function returns a list of class “roc” invisibly. See roc for more details.

Examples

data(aSAH)

rocobj <- plot.roc(aSAH$outcome, aSAH$s100b, type="n")
lines(rocobj, type="b", pch=21, col="blue", bg="grey")

# Without using 'lines':
rocobj <- plot.roc(aSAH$outcome, aSAH$s100b, type="b", pch=21, col="blue", bg="grey")