MVKD_loop: Performs LR calculation on a set of speakers

In justinjhlo/fvclrr: Likelihood Ratio Calculation and Testing in Forensic Voice Comparison

Performs LR calculation on a set of speakers

Description

Iterates through all pairings in a set of test speakers and calculates the likelihood ratio for each speaker-pair

Usage

MVKD_loop(
  data,
  test_speakers = NULL,
  bg_speakers = NULL,
  data_col = NULL,
  test_data = NULL,
  test_data_col = NULL,
  cross_full = TRUE
)

Arguments

data	A data frame. The first column identifies speakers.
test_speakers	(optional) A vector. Specifies the set of speakers for which LR calculations should be derived. Takes all speakers from data if unspecified.
bg_speakers	(optional) A vector. Specifies the set of speakers to form the background model for LR calculations. Equal to test_speakers if unspecified.
data_col	(optional) A vector. Specifies which columns in data to take into account in LR calculation. Uses all available columns if unspecified (excludes first column, which identifies speakers).
test_data	(optional) A data frame in the same format as data. If specified, offender/disputed-speaker data will be taken from here. Suspect/known-speaker data and background data will be taken from data.
test_data_col	(optional) A vector. Specifies which columns in data to take into account in LR calculation. Follows data_col if unspecified.
cross_full	(optional) Boolean. When test_data and test_data_col are specified, determines if the full set of data from each speaker are used in the comparison. Default TRUE. If FALSE, suspect data come from first half of data and questioned data come from second half of test_data, to simulate the scenario when test_data is not specified. Useful for keeping number of data points constant, in the case of comparisons involving non-contemporaneous recordings or mismatched conditions and the results of which are compared with contemporaneous comparisons.

Value

A named list of 3 items:

• likelihood_ratio_matrix: A data frame. Rows and columns are named after the speaker identifiers. Each row and column represents a speaker as suspect and offender respectively, and each cell contains a single LR score.

• cllr: Numeric. Reports the logLR cost.

• eer: Numeric. Reports the equal error rate (between 0 and 1).

justinjhlo/fvclrr documentation built on June 27, 2022, 11:19 a.m.