R/ChiSquare.R

In LearnNonparam: 'R6'-Based Flexible Framework for Permutation Tests

#' @title `r ChiSquare$private_fields$.name`
#' 
#' @description Performs chi-square test on contingency tables.
#' 
#' @aliases table.chisq
#' 
#' @examples
#' t <- pmt(
#'     "table.chisq", n_permu = 0
#' )$test(Table5.4.2)$print()
#' 
#' t$type <- "asymp"
#' t
#' 
#' @export
#' 
#' @importFrom R6 R6Class
#' @importFrom stats pchisq


ChiSquare <- R6Class(
    classname = "ChiSquare",
    inherit = ContingencyTableTest,
    cloneable = FALSE,
    public = list(
        #' @description Create a new `ChiSquare` object.
        #' 
        #' @template pmt_init_params
        #' 
        #' @return A `ChiSquare` object.
        initialize = function(
            type = c("permu", "asymp"),
            n_permu = 1e4
        ) {
            self$type <- type
            self$n_permu <- n_permu
        }
    ),
    private = list(
        .name = "Chi-Square Test on Contingency Table",

        .define = function() {
            private$.statistic_func <- function(data) {
                r <- nrow(data)
                c <- ncol(data)

                expect <- tcrossprod(
                    .rowSums(data, r, c),
                    .colSums(data, r, c)
                ) / sum(data)

                function(data) sum((data - expect)^2 / expect)
            }
        },

        .calculate_side = function() {
            private$.side <- "r"
        },

        .calculate_p = function() {
            r <- nrow(private$.data)
            c <- ncol(private$.data)

            private$.p_value <- get_p_continous(
                private$.statistic, "chisq", "r", df = (r - 1) * (c - 1)
            )
        }
    )
)