R/print_fisher_text.R

In Alaburda/statistician: Making Easy Statistical Reports

#' Print the results of a chi-square test
#'
#' @param x A contingency table (passed as \code{table} or \code{matrix}) or
#'     an object of type "htest" returned by \code{\link{chisq.test}}. Can
#'     also handle objects returned by \code{\link[spgs]{chisq.unif.test}}
#'     from the \code{spgs} package.
#' @param es Boolean. Should the phi coefficient be printed as a
#'     measure of effect size. See details.
#' @param correct Boolean. Apply a continuity correction? See
#'     \code{\link{chisq.test}}. Only has an effect if the chi-square-test
#'     is computed by this function, i.e., if \code{x} is a contingency
#'     table. The default value is \code{FALSE}.
#' @param decimals How many decimals should be printed
#' @param decimals_p How many decimals should be printed for the p-value
#'     (defaults to 3)
#'
#' @return A string describing the results of the chi-square test to be
#'     printed in Rmarkdown documents.
#'
#' @details
#'
#' The argument \code{es} only has an effect if \code{x} is passed as a 2x2
#' contingency table. In this case, the phi coefficient is computed as
#' a measure of effect size (see Cohen, 1988, page 223).
#'
#' @references
#' Cohen, J. (1988). Statistical power analysis for the behavioral sciences
#'     (2nd ed.). Hillsale, NJ: Lawrence Erlbaum.
#'
#' @examples
#'
#' # Pass a matrix
#' x <- matrix(c(12, 5, 7, 7), ncol = 2)
#' print_chi2(x) # does not use continuity correction by default
#' print_chi2(x, correct = TRUE) # uses continuity correction
#'
#' # Pass a table
#' tab <- table(rbinom(150, 1, 0.5), rbinom(150, 1, 0.1))
#' print_chi2(tab, correct = FALSE)
#'
#' # Pass a chi-squared test object
#' print_chi2(chisq.test(tab, correct = FALSE))
#'
#'
#' @author Martin Papenberg \email{martin.papenberg@@hhu.de}
#'
#' @importFrom stats chisq.test
#'
#' @export
#'

print_fisher_text <- function(data, x, y, var1_name, var2_name) {
  fisher.obj <- fisher.test(table(data[,x],data[,y]))

  fisher_rs <- glue::glue("{format_p(fisher.obj$p.value)}")


  if (fisher.obj$p.value < 0.05) {
    glue::glue("Atlikus Fisher tikslų testą rasta statistiškai reikšminga asociacija tarp {var1_name} ir {var2_name} ({fisher_rs}).")
  } else {
    glue::glue("Atlikus Fisher tikslų testą asociacija tarp {var1_name} ir {var2_name} nebuvo statistiškai reikšminga ({fisher_rs}).")
  }
}