poseticDataAnalysis (version 1.0.0)

ExactMRP: Computing Mutual Ranking Probabilities (MRP).

Description

Computes the MRP matrix of a poset. The MRP associated to \(a\leq b\), with \(a\) and \(b\) two elements of the input poset, is the share of linear extensions of it where \(b\) dominates \(a\). The linear extensions are computed according to the algorithm given in Habib M, Medina R, Nourine L and Steiner G (2001).

Usage

ExactMRP(poset, output_every_sec = NULL)

Value

A list of two elements: 1) the MRP matrix and 2) the number of linear extensions generated to compute it.

Arguments

poset

An object of S4 class POSet representing the poset whose MRP are computed. Argument poset must be created by using any function contained in the package aimed at building object of S4 class POSet (e.g. POSet(), LinearPOSet(), ProductPOSet(), ...) .

output_every_sec

Integer specifying a time interval (in seconds). By specifying this argument, during the execution of ExactMRP a message reporting the number of linear extensions progressively generated is printed on the R-Console, every output_every_sec seconds.

References

Habib M, Medina R, Nourine L and Steiner G (2001). Efficient algorithms on distributive lattices. Discrete Applied Mathematics, 110, 169-187. https://doi.org/10.1016/S0166-218X(00)00258-4.

Examples

# \donttest{
el1 <- c("a", "b", "c", "d")
el2 <- c("x", "y")
el3 <- c("h", "k")
dom <- matrix(c(
  "a", "b",
  "c", "b",
  "b", "d"
), ncol = 2, byrow = TRUE)

pos1 <- POSet(elements = el1, dom = dom)

pos2 <- LinearPOSet(elements = el2)

pos3 <- LinearPOSet(elements = el3)

pos <- ProductPOSet(pos1, pos2, pos3)

MRP <- ExactMRP(pos, output_every_sec=1)
# }