R/num_summary.R

In m-clark/tidyext: Tidy Extensions for Data Processing

#' @title Get numerical summaries
#' @description Essentially a slight tweak to the base R summary.
#'
#' @param x A numeric or logical variable
#' @param digits Argument to \code{round}. Default is 1.
#' @param extra Add things like number distinct, number of zeros, and more as I
#'   think of them.
#'
#' @details  Takes a numeric variable and provides sample size, mean, standard
#'   deviation, min, first quartile, median, third quartile, and max, and number
#'   of NAs. Extras include the number of distinct values, and the number of
#'   zeros.
#' @return A data.frame containing those values.
#' @importFrom stats na.omit
#' @examples
#' library(tidyext)
#' num_summary(c(1:10, NA))
#' num_summary(c('1','2','3'))
#'
#' @export
num_summary <- function(x, digits = 1, extra = FALSE) {

  # initial check of variable type
  test_x <- tryCatch(
    as.numeric(x),
    warning = function(c) {
      msg <- conditionMessage(c)
      invisible(structure(msg, class = "try-warning"))
    }
  )

  if(class(test_x) == 'try-warning')
    stop('Need something numeric or which can reasonably be converted to such.
     \nThe current variable would introduce NAs by coercion.')

  x <- as.numeric(x)

  d <- dplyr::tibble(
    N = length(na.omit(x)),
    data.frame(t(c(summary(x)))),
    SD = sd(x, na.rm = TRUE),
    `% Missing` = round(100*sum_NA(x)/length(x))
  ) %>%
    # currently there is a bug that keeps this from working
    # rename_all(funs(gsub(., pattern='.', replacement=''))) %>%
    rename(Q1 = X1st.Qu.,
           Q3 = X3rd.Qu.) %>%
    select(N, Mean, SD, everything(), -matches('NA')) # drop summary() NA if present

  colnames(d) <- gsub(colnames(d), pattern = '\\.', replacement = '')

  if (extra) {
    d <- d %>%
      mutate(
        Distinct = n_distinct(na.omit(x)),
        Zeros = sum(x == 0, na.rm = TRUE)
      )
  }

  d %>% dplyr::mutate_if(is.numeric, round, digits = digits)
}