R/lsos.R

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#' Improved list of objects
#' 
#' @param ... to be passed along to internal
#' @param n to be given to head
#' 
#' @importFrom utils object.size
#' @export
#' @author \href{http://stackoverflow.com/users/143305/dirk-eddelbuettel}{Dirk Eddelbuettel}
#' @references \url{http://stackoverflow.com/questions/1358003/tricks-to-manage-the-available-memory-in-an-r-session}
lsos <- function(..., n=10) {
  .ls.objects(..., order.by="Size", decreasing=TRUE, head=TRUE, n=n)
}

# improved list of objects
.ls.objects <- function (pos = 1, pattern, order.by,
                         decreasing=FALSE, head=FALSE, n=5) {
  napply <- function(names, fn) sapply(names, function(x)
    fn(get(x, pos = pos)))
  names <- ls(pos = pos, pattern = pattern)
  obj.class <- napply(names, function(x) as.character(class(x))[1])
  obj.mode <- napply(names, mode)
  obj.type <- ifelse(is.na(obj.class), obj.mode, obj.class)
  obj.size <- napply(names, object.size)
  obj.dim <- t(napply(names, function(x)
    as.numeric(dim(x))[1:2]))
  vec <- is.na(obj.dim)[, 1] & (obj.type != "function")
  obj.dim[vec, 1] <- napply(names, length)[vec]
  out <- data.frame(obj.type, obj.size, obj.dim)
  names(out) <- c("Type", "Size", "Rows", "Columns")
  if (!missing(order.by))
    out <- out[order(out[[order.by]], decreasing=decreasing), ]
  if (head)
    out <- head(out, n)
  out
}