R: Add a ROC line to a ROC plot

lines.roc {pROC} | 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, 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")

[Package pROC version 1.16.0 Index]