R/04_summarizex.R

In moodymudskipper/tidyx: modified tidyverse functions for interractive use

#' summarize with grouping
#'
#' If \code{.by} is given, data is grouped just for summarize operation.
#'
#' Prefer standard grouping notation for a sequence of operations.
#'
#' @inheritParams dplyr::summarize
#' @param .by a vector or list of variables as characters or given by \code{vars}
#'
#' @export
#'
#' @examples
#' iris[c(1:2,51:52),] %>% summarizex(z= mean(Sepal.Length),.by= vars(Species))
#' iris[c(1:2,51:52),] %>% summarizex(z= mean(Sepal.Length),.by= "Species")
summarizex <- function(.data, ..., .by = NULL, .unnest = TRUE)
{

  # 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(is.character(by))
    by <- dplyr:::tbl_at_syms(data, by)

  #if (identical(rlang::enquo(.by)[[2]], quote(NULL))) x <-  dplyr::summarize(.data, ...)
  if(is.null(by))
    x <-  dplyr::summarize(.data, ...)
  else  {
    groups <- dplyr::group_vars(.data)
    x <- dplyr::group_by(.data,!!!.by, add = TRUE)
    x <- dplyr::summarize(x, ...)
    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))
  }
  if (.unnest && "list" %in% purrr::map_chr(x,typeof)) tidyr::unnest(x) else x
}

#' @export
at <- function(.vars, .fun, .key = "data"){
  eval.parent(list(map_dfc(.vars,.fun)))
}

# mtcars %>%
#   group_by(cyl) %>%
#   summarizex(at(lst(mpg, disp, hp, drat),mean),
#              wt = max(wt))
#
# mtcars %>%
#   summarizex(at(lst(mpg, disp, hp, drat),mean), wt = max(wt), .by = "cyl")