calibrate.set: Calculate the calibrated set of idea LRs

Description

Calculates and returns the calibrated set of ideal' LRs from the observed LRs using the penalised adjacent violators algorithm. This is very much a rewrite of Nico Brummer's optloglr()` function for Matlab.

Usage

calibrate.set(
  LR.ss,
  LR.ds,
  method = c("raw", "laplace"),
  ties = c("none", "primary", "secondary", "tertiary")
)

Value

a list with two items:

LR.cal.ss: calibrated LRs for the comparison for same set
LR.cal.ds: calibrated LRs for the comparison for different set

Arguments

LR.ss: a vector of likelihood ratios for the comparisons of items known to be from the same source
LR.ds: a vector of likelihood ratios for the comparisons of items known to be from different sources
method: the method used to perform the calculation, either "raw" or "laplace"
ties: method to solve ties in the predictors list, either "none" (not solved) or "primary", "secondary" or "tertiary" (passed to the isotone::gpava() function)

Author

David Lucy

Details

This is an internal function, and is not meant to be called directly. However it has been exported just in case.

References

Ramos, D. & Gonzalez-Rodriguez, J. (2008) Cross-entropy analysis of the information in forensic speaker recognition; IEEE Odyssey.

de Leeuw, J. & Hornik, K. & Mair, P., (2009), Isotone Optimization in R: Pool-Adjacent-Violators Algorithm (PAVA) and Active Set Methods, https://www.jstatsoft.org/article/view/v032i05