R/09_spreadx.R

In moodymudskipper/tidyx: modified tidyverse functions for interractive use

#' spreadx
#'
#' @inheritParams tidyr::spread
#' @param by @param .by a vector or list of variables as characters or given
#'   by \code{vars}
#'
#' @export
#'
#' @examples
#' dat <- structure(list(
#'   V1 = c("startTime", "max", "min", "EndTime", "avg",
#'          "startTime", "max", "min", "EndTime", "avg"),
#'   V2 = c(1L, 3L, 1L, 2L, 2L, 2L, 3L, 4L, 5L, 6L)),
#'   .Names = c("V1", "V2"), class = "data.frame",
#'   row.names = c(NA, -10L))
#' dat %>%  spreadx(V1,V2, by = vars(cumsum(V1=="startTime")))
spreadx <- function(data, key, value, fill = NA, convert = FALSE, drop = TRUE,
                    sep = NULL, by = NULL){

  # store names of by calls that were not created with an explicit name
  # they will be removed in the ends
  tmp_by_cols <- get_tmp_by_cols(data, by)

  # if by is character, need to transform it
  if (is.character(by))
    by <- dplyr:::tbl_at_syms(data, by)

  if (is.null(by))
    # regular spread
    x <- tidyr::spread(data, key, value, fill, convert, drop, sep)
  else  {
    # record group state, group by additional new cols, spread, set groups back
    groups <- dplyr::group_vars(data)
    x <- dplyr::group_by(data,!!!by, add = TRUE)
    x <- tidyr::spread(x, !!rlang::enquo(key), !!rlang::enquo(value),
                       fill, convert, drop, sep)
    x <- dplyr::group_by(x, !!!rlang::syms(groups), add = FALSE)
    # remove temporary by cols
    if (length(tmp_by_cols)) x <- select(x,-!!sym(tmp_by_cols))
  }
  x
}