R/agg_tbl.R

In Triamus/mandat: Manage Data Fast with data.table Function Wrappers

#' Aggregates a data.table
#' @param dt A data.table object
#' @param metric A vector of numeric variable(s) to aggregate
#' @param metric_name A vector of variable name(s) for the numeric variable(s) to aggregate. Defaults to metric.
#' @param dimension A vector of dimension variable(s) to aggregate by
#' @param agg_fn An aggregation function
#' @param na.rm logical. Should missing values (including NaN) be removed?
#' @return Returns a data.table
#' @export
#' @import data.table
#' @importFrom methods getFunction
#' @importFrom stats setNames
#' @examples
#' \dontrun{
#' to follow
#' }

agg_tbl <-
  function(dt, metric, metric_name = metric,
           dimension, agg_fn = "sum", na.rm = TRUE) {

    #options(datatable.verbose=TRUE)
    e <- function(x) getFunction(agg_fn)(x, na.rm = na.rm)

    dt[, setNames(lapply(.SD, e), metric_name),
       keyby = dimension, .SDcols = metric][]
  }