ASTAR.Rd
This function estimates the exact MLE of a Mallows-Binomial distribution using an A* tree search algorithm proposed in Pearce and Erosheva (2022). Algorithm may be very slow when number of objects exceeds 15, but is often still tractable for larger J when consensus is strong.
ASTAR(rankings, ratings, M, keep_nodes = FALSE)
A matrix of rankings, potentially with attribute "assignments" to signify separate reviewer assignments. One ranking per row.
A matrix of ratings, one row per judge and one column per object.
Numeric specifying maximum (=worst quality) integer rating.
Boolean specifying if function should retain the list of open nodes traversed during A*
tree search. Defaults to FALSE
.
A list with elements pi0
, the estimated consensus ranking MLE, p
, the
estimated object quality parameter MLE, theta
, the estimated scale parameter MLE, and
numnodes
, number of nodes traversed during algorithm and a measure of computational complexity.
If keep_nodes == TRUE
, then the list also contains nodes
, a matrix of open nodes remaining
at the end of search. If multiple MLEs are found, pi0
, p
, and theta
are returned a matrix elements, with
one row per MLE.
data("ToyData1")
ASTAR(ToyData1$rankings,ToyData1$ratings,ToyData1$M,keep_nodes=TRUE)
#> $pi0
#> [1] 1 2 3
#>
#> $p
#> [1] 0.125 0.125 0.750
#>
#> $theta
#> [1] 1e+08
#>
#> $num_nodes
#> [1] 5
#>
#> $nodes
#> [,1] [,2] [,3]
#> [1,] 2 NA 6.9158
#> [2,] 3 NA 9.4300
#> [3,] 1 3 8.6419
#>