# Generator for the approximated computation of the mean value of functions over linear extensions. `BuildBubleyDyerEvaluationGenerator` creates an object of S4 class `BuildBubleyDyerEvaluationGenerator`, for the estimation of the mean values of the input functions, over linear extensions sampled according to the Bubley-Dyer procedure. Actually, this function does not perform the computation of mean values, but just generates the object that will compute them by using function `BubleyDyerEvaluation`. ```r BuildBubleyDyerEvaluationGenerator(poset, seed, f1, ...) ``` ## Arguments - `poset`: An object of S4 class `POSet` representing the poset from which linear extensions are generated. Object `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()`, ...) . - `seed`: Positive integer to initialize random linear extension generation. Set `seed=NULL` for random initialization. - `f1`: The function whose mean value is to be computed. `f1` must be an R-function having as a single parameter a linear extension of `poset` and returning a numerical matrix. - `...`: Further functions whose mean values are to be computed. ## Returns An object of S4-class `BuildBubleyDyerEvaluationGenerator`. ## Examples ```r 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) # median_distr computes the frequency distribution of median profile elements <- POSetElements(pos) median_distr <- function(le) { n <- length(elements) if (n %% 2 != 0) { res <- (elements == le[(n + 1) / 2]) } else { res <- (elements == le[n / 2]) } res <- as.matrix(res) rownames(res) <- elements colnames(res) <- "median_distr" return (as.matrix(res)) } BDgen <- BuildBubleyDyerEvaluationGenerator(poset = pos, seed = NULL, median_distr) ```

BuildBubleyDyerEvaluationGenerator function