New package:

About this list Date view Thread view Subject view Author view Attachment view

From: David Brahm (
Date: Tue 04 Dec 2001 - 03:25:02 EST

Message-id: <15371.42846.422155.287658@gargle.gargle.HOWL>

A new package "" is available on CRAN, to create and maintain databases
that work more like the S-Plus model.

Here's the official Description for (v1.2):
  Create and maintain delayed-data packages (DDP's). Data stored in
  a DDP are available on demand, but do not take up memory until requested.
  You attach a DDP with, then read from it and assign to it in
  a manner similar to S-Plus, except that you must run to
  actually commit to disk.

Here's a very abbreviated (Unix) example:"/tmp/mydir") # Open package:mydir in pos=2
  assign("x1", matrix(1, 1000, 1000), 2) # Put data there # Commit to disk
  detach(2) # Detach package:mydir"/tmp/mydir") # Re-attach it, no resources used
  dim(x1) # x1 is loaded only when needed!
  find("x1") # It still lives in package:mydir is the end result of my post "Reading and writing to S-like databases",
sent to R-help on Sep 28, 2001. Thanks to all who responded, especially
Dr. Agustin Lobo <> and (by reference) Ray Brownrigg
<>, who suggested using delay(); Martin Maechler
<>, Thomas Lumley <>, Brian
D. Ripley <>, and Peter Dalgaard
<>, who helped me with platform independence issues;
and Kurt Hornik <>, who cleaned it up for CRAN.

I have one concern: relies heavily on delay(), whose documentation says:
  This is an experimental feature and its addition is purely for
  evaluation purposes.
Is there any plan to deprecate delay()?

Feedback is welcome!

                              -- David Brahm (

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-announce mailing list -- Read Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

About this list Date view Thread view Subject view Author view Attachment view

This archive was generated by hypermail 2.1.3 : Thu 17 Jan 2002 - 11:16:02 EST