extractAUC: Extract AUC
In BayesianFROC: FROC Analysis by Bayesian Approaches

Extract AUC for both srsc and MRMC data.

extractAUC(
  StanS4class,
  dig = 3,
  summary = TRUE,
  new.imaging.device = TRUE,
  print_CI_of_AUC = TRUE
)

`StanS4class`	An S4 object of class `stanfitExtended` which is an inherited class from the S4 class `stanfit`. This R object is a fitted model object as a return value of the function `fit_Bayesian_FROC()`. To be passed to `DrawCurves()` ... etc
`dig`	digits of estimates.
`summary`	Logical: `TRUE` of `FALSE`. Whether to print the verbose summary. If `TRUE` then verbose summary is printed in the R console. If `FALSE`, the output is minimal. I regret, this variable name should be verbose.
`new.imaging.device`	Logical: `TRUE` of `FALSE`. If TRUE (default), then open a new device to draw curve. Using this we can draw curves in same plain by new.imaging.device=FALSE.
`print_CI_of_AUC`	Logical, if `TRUE` then Credible intervals of AUCs for each modality are plotted.