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

 ROC R Documentation

Plot the Receiver Operating Characteristic Curve

Description

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

Usage

``````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

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

perbrock/sensR documentation built on Nov. 5, 2023, 10:41 a.m.