Time Dataset was Last Changed

DESCRIPTION:

Returns the time at which a permanently stored version of a dataset (object) was last modified.

USAGE:

dataset.date(name, where=1, meta = 0, date.format=10) 

REQUIRED ARGUMENTS:

name
character string naming a dataset stored on database where.

OPTIONAL ARGUMENTS:

where
a number identifying a database in the search list.
meta
if supplied, for example, as "methods" or "help", look in the corresponding meta-database instead of the ordinary database.
date.format
integer specifying in which format the dataset date should be returned. Currently recognized values are 1 for an integer like 717805635, measuring seconds since 1 January 1970 00:00 GMT; 10 for a string like "Tue Sep 29 15:27:15 1992"; and 11 for "92.09.29 15:27".

VALUE:

if where refers to a directory database, the time of the last modification to the permanently stored version of this dataset. Note that datasets are not permanently stored until the end of a top level expression unless you use synchronize() or assign(..., immediate=T) to force early storage.

The return value "NA" (or -1 for integer format) means that the dataset does not exist on the database. "0" (or 0 for integer format) is returned for the special dataset .Random.seed, whether it exists or not. Zero is also returned for any object in a non-directory database.

SEE ALSO:

, , .

EXAMPLES:

  x <- 10 
  dataset.date("x") 
  d <- dataset.date("x", date.format=1)    # as number 
  x <- 20 
  # Compute time between assignemnts:
  dataset.date("x", date.format=1) - d