# ROC: Plot the Receiver Operating Characteristic Curve In sensR: Thurstonian Models for Sensory Discrimination

## Description

The function computes and plots the empirical ROC (receiver operating characteristic) curve.

## Usage

 ```1 2 3 4 5 6 7 8 9``` ```ROC(object, ...) ## Default S3 method: ROC(object, se.d, scale = 1, length = 1000, fig = TRUE, se.type = c("CI", "SE"), CI.alpha = 0.05, ...) ## S3 method for class 'anota' ROC(object, length = 1000, fig = TRUE, se.type = c("CI", "SE"), CI.alpha = 0.05, ...) ```

## Arguments

 `object` the class of the object defines, which of the methods is invoked. If obejct is a single element numeric vector it is taken as a d-prime value and the default method is invoked. If the object is of class `anota`, the method for `anota` objects is invoked. `se.d` a unit length vector with the standard error of d-prime. If supplied confidence intervals or standard errors are plotted `scale` a unit length vector giving the ratio of scale (ie. standard deviation) of the latent distribution for the no-class items relative to that of the yes-class items `length` the length of the vectors to be plotted. Longer vectors gives more smooth curves. `fig` Should a plot be produced? `se.type` The type of band for the ROC curve, `"CI"` for confidence interval and `"SE"` for standard error. `CI.alpha` the type I level of the confidence interval of AUC `...` additional arguments to `plot` and `lines`

## Details

The function currently ignores the variance of the scale in the computation of the uncertainty of the ROC curve.

## Value

The function makes a plot of the ROC curve, and if `se.d` is supplied, standard errors or confidence intervals for the curve are added to the plot.

The function also (invisibly) returns a list with the following components

 `ROCx` x-coordinates to the ROC curve `ROCy` y-coordinates to the ROC curve

If `se.d` is supplied, the object also contains

 `lower` y-coordinates to the lower limit `upper` y-coordinates to the upper limit

## Author(s)

Rune Haubo B Christensen

## Examples

 ```1 2 3 4 5 6 7``` ```## ROC.default: (mat <- matrix(c(8, 17, 1, 24), 2, byrow = TRUE)) (d.prime <- SDT(mat, "probit")) ROC(d.prime) ## ROC.anota: fm1 <- AnotA(8, 25, 1, 25) ROC(fm1) ```

### Example output  ```     [,1] [,2]
[1,]    8   17
[2,]    1   24
 1.282987
```

sensR documentation built on Feb. 11, 2020, 1:10 a.m.