Add a ROC line to a ROC plot

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, subset, na.action, ...)
# 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.

subset,na.action

arguments for model.frame

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.

See also

roc, plot.roc

Examples

# Create a few ROC curves:
data(aSAH)
roc.s100b <- roc(aSAH$outcome, aSAH$s100b)
roc.wfns <- roc(aSAH$outcome, aSAH$wfns)

# We need a plot to be ready
plot(roc.s100b, type = "n") # but don't actually plot the curve

# Add the line
lines(roc.s100b, type="b", pch=21, col="blue", bg="grey")

# Add the line of an other ROC curve
lines(roc.wfns, type="o", pch=19, col="red")


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