R/guessdk_lik.R

In soodoku/guess: Adjust Estimates of Learning for Guessing

#' guessdk_lik
#' @description Likelihood function for data with Don't Know. Used Internally.
#' @keywords internal
#' 
#' @param x    lgg, lgk, lgc, lkk, lcg, lck, and lcc
#' @param g1   guess
#' @param data transition matrix

guessdk_lik <- function(x, g1 = x[8], data) {

  lgg <- x[1]
  lgk <- x[2]
  lgc <- x[3]
  lkk <- x[4]
  lcg <- x[5]
  lck <- x[6]
  lcc <- x[7]

  vec <- NA
  vec[1] <- (1 - g1) * (1 - g1) * lgg
  vec[2] <- (1 - g1) * g1 * lgg + (1 - g1) * lgk
  vec[3] <- (1 - g1) * lgc
  vec[4] <- (1 - g1) * g1 * lgg
  vec[5] <- g1 * g1 * lgg + g1 * lgk + lkk
  vec[6] <- g1 * lgc
  vec[7] <- (1 - g1) * lcg
  vec[8] <- g1 * lcg + lck
  vec[9] <- lcc

  -sum(data * log(vec))
}