R/stat_stars.R

In NicolasJBM/writer: Functions and interfaces to support academic writing with R

#' Add stars to a vector of coefficients based on the p-value.
#' @param coeff      Numeric vector. Coefficients.
#' @param pval       Numeric vector. Corresponding p-values.
#' @param thresholds Numeric vector. three values indicating the cit-off p-values.
#' @param digits     Integer. Number of digits for rounding.
#' @return Character vector with coefficients formatted for publication.
#' @importFrom dplyr mutate
#' @importFrom dplyr case_when
#' @importFrom tibble tibble
#' @export

stat_stars <- function(coeff = NULL, pval = NULL, thresholds = c(0.01,0.05,0.10), digits = 3) {
  
  # Check entries
  stopifnot(
    !is.null(coeff),
    !is.null(pval)
  )
  
  # Create a visible binding
  fcoeff <- NULL
  stars <- NULL
  
  x <- tibble(coeff = coeff, pval = pval) %>%
    mutate(stars = "   ") %>%
    mutate(
      stars = case_when(
        pval < thresholds[[1]] ~ "***",
        pval >= thresholds[[1]] & pval < thresholds[[2]] ~ "** ",
        pval >= thresholds[[2]] & pval < thresholds[[3]]  ~ "*  ",
        TRUE                   ~ "   "
      )
    ) %>%
    mutate(coeff = format(round(coeff, digits = digits), nsmall = digits)) %>%
    mutate(fcoeff = case_when(
      coeff >= 0 ~ paste0(" ", coeff),
      TRUE ~ paste0("", coeff)
    )) %>%
    mutate(fcoeff = paste0(fcoeff, stars))
  
  return(x$fcoeff)
}