R/rowwise.R

In mtfairbanks/gdt: Tidy Interface to 'data.table'

#' Convert to a rowwise tidytable
#'
#' @description
#' Convert to a rowwise tidytable.
#'
#' @param .df A data.frame or data.table
#'
#' @export
#'
#' @examples
#' df <- tidytable(x = 1:3, y = 1:3 * 2, z = 1:3 * 3)
#'
#' # Compute the mean of x, y, z in each row
#' df %>%
#'   rowwise() %>%
#'   mutate(row_mean = mean(c(x, y, z)))
#'
#' # Use c_across() to more easily select many variables
#' df %>%
#'   rowwise() %>%
#'   mutate(row_mean = mean(c_across(x:z))) %>%
#'   ungroup()
rowwise <- function(.df) {
  UseMethod("rowwise")
}

#' @export
rowwise.tidytable <- function(.df) {
  set_class(.df, c("rowwise_tt", tidytable_class()))
}

#' @export
rowwise.grouped_tt <- function(.df) {
  .df <- ungroup(.df)
  rowwise(.df)
}

#' @export
rowwise.rowwise_tt <- function(.df) {
  .df
}

#' @export
rowwise.data.frame <- function(.df) {
  .df <- as_tidytable(.df)
  rowwise(.df)
}