## ----include = FALSE----------------------------------------------------------
knitr::opts_chunk$set(collapse = TRUE, comment = "#>")
library(meow)

## ----eval = FALSE-------------------------------------------------------------
# idx    <- which(admin != 0, arr.ind = TRUE)
# persons <- unique(idx[, 1])
# items <- unique(idx[, 2])
# resp   <- R[idx]

## ----eval = FALSE-------------------------------------------------------------
# loglik <- function(theta) {
#   p <- stats::plogis(item$a[item_j] * (theta[person] - item$b[item_j]))
#   sum(resp * log(p) + (1 - resp) * log(1 - p))
# }
# est <- stats::optim(pers$theta, loglik, lower = -4, upper = 4,
#                     method = "L-BFGS-B", control = list(fnscale = -1))