roc_curves {MRMCaov}

ROC Performance Curves

Description

Calculation of ROC curve true positive rate (TPR) and false positive rate (FPR) pairs for values of a numeric rating of a true binary response.

Usage

roc_curves(...)

## Default S3 method:
roc_curves(truth, rating, groups = list(), method = "empirical", ...)

## S3 method for class 'mrmc'
roc_curves(x, ...)

## S3 method for class 'stmc'
roc_curves(x, ...)

parameters(x, ...)

## S3 method for class 'roc_curve'
parameters(x, ...)

## S3 method for class 'roc_curves'
parameters(x, ...)

## S3 method for class 'mrmc'
parameters(x, ...)

## S3 method for class 'stmc'
parameters(x, ...)

## S3 method for class 'roc_curve'
points(
  x,
  metric = c("specificity", "sensitivity"),
  values = seq(0, 1, length = 101),
  ...
)

## S3 method for class 'roc_curves'
points(
  x,
  metric = c("specificity", "sensitivity"),
  values = seq(0, 1, length = 101),
  ...
)

## S3 method for class 'empirical_curve'
points(
  x,
  metric = c("specificity", "sensitivity"),
  values = NULL,
  which = c("curve", "curves", "observed"),
  ties = max,
  ...
)

## S3 method for class 'empirical_curves'
points(
  x,
  metric = c("specificity", "sensitivity"),
  values = NULL,
  which = c("curve", "curves", "observed"),
  ties = max,
  ...
)

## S3 method for class 'roc_curve'
mean(x, ...)

## S3 method for class 'roc_curves'
mean(x, ...)

## S3 method for class 'binormal_curves'
mean(x, method = c("points", "parameters"), ...)

Arguments

...

arguments passed from the mean() method to points().

truth

vector of true binary statuses.

rating

vector of numeric ratings.

groups

list or data frame of grouping variables of the same lengths as truth and rating.

method

character string indicating the curve type as "binormal", "binormalLR", "empirical", or "trapezoidal" or the averaging of binormal curves over "points" or "parameters".

x

object returned by mrmc or roc_curves for which to compute points on or to average over the curves.

metric

reader performance metric to which the values correspond.

values

numeric vector of values at which to compute ROC curve points, or NULL for default empirical values as determined by which.

which

character string indicating whether to use curve-specific observed values and 0 and 1 ("curve"), the combination of these values over all curves ("curves"), or only the observed curve-specific values ("observed").

ties

function determining empirical roc points returned in cases of ties.

Value

Function roc_curves returns an roc_curve class object of a single estimated ROC curve or an roc_curves class object of grouped ROC curves. Function parameters extracts the parameters that define the curves, points returns a data frame of points on individual curves, and means returns points on averaged curves (Chen and Samuelson, 2014).

References

Chen W and Samuelson FW (2014). The average receiver operating characteristic curve in multireader multicase imaging studies. The British Journal of Radiology, 87(1040): 20140016.

See Also

plot

Examples

curves <- with(VanDyke,
  roc_curves(truth, rating, groups = list(Test = treatment, Reader = reader))
)
points(curves)
mean(curves)