R/lls.R

In JVAdams/jvamisc: A Collection of Utility Functions

#' List All Members of an Environment.
#'
#' Generate a descriptive list of all members of an environment.
#' @param pos
#'   A scalar of the environment, search path index, or package of interest,
#'   default 1.
#' @param pat
#'   Regular expression pattern specifying which members to return,
#'   default "" for all members.
#' @return
#'   A data frame with the name, class, dimension, and size of each member of
#'   the environment.
#' @export
#' @references
#'   Based on a method posted by Bendix Carstensen on 10 Jan 2007 on R-help
#'   \href{https://stat.ethz.ch/pipermail/r-help/2007-January/123403.html}{[link]}.
#' @examples
#' \dontrun{
#' lls()
#' }

lls <- function(pos=1, pat="") {
  # modification of original function
  # http://tolstoy.newcastle.edu.au/R/e2/help/07/01/8286.html
  # Bendix Carstensen - 10 Jan 2007
  # see also R.oo ll() function
  dimx <- function(dd) {
    if (is.null(dim(dd))) {
      length(dd)
    } else {
      dim(dd)
    }
  }
  lll <- ls(pos=pos, pattern=pat)
  if (length(lll) > 0) {
    x <- data.frame(array(dim=c(length(lll), 3),
      dimnames=list(lll, c("class", "ndim", "size"))))
    y <- rep(NA, length(lll))
    for(i in 1:length(lll)) {
      x$class[i] <- paste(eval(parse(text=paste("class(", lll[i], ")"))),
        collapse=" ")
      x$ndim[i] <- length(eval(parse(text=paste("dimx(", lll[i], ")"))))
      x$size[i] <- paste(eval(parse(text=paste("dimx(", lll[i], ")"))),
        collapse=" x ")
      y[i] <- prod(eval(parse(text=paste("dimx(", lll[i], ")"))))
    }
  }
  x$ndim[x$class=="function"] <- 0
  x[order(-x$ndim, -y, x$class), ]
}