From bates@stat.wisc.edu  Tue Feb 24 18:10:49 1998
From: bates@stat.wisc.edu (Douglas Bates)
Date: 24 Feb 1998 12:10:49 -0600
Subject: Representation of data in libraries
In-Reply-To: Ralf Goertz's message of Tue, 24 Feb 1998 18:02:29 +0100
Message-ID: <6rhg5ox49i.fsf@verdi.stat.wisc.edu>

At present the example data sets in R libraries are to be given as
expressions that can be read directly into R.  For example, the acid.R 
file in the main library looks like
 acid <- data.frame(
  carb  = c(0.1, 0.3, 0.5, 0.6, 0.7, 0.9),
  optden = c(0.086, 0.269, 0.446, 0.538, 0.626, 0.782), row.names = paste(1:6))

This is great when you have only a few observations.  I have one
example data set with over 9000 rows and 17 variables.  Even when I
set -v 40, I exhaust the available memory trying to read it in as a
data.frame.  I believe this is because of the recursive nature of the
parsing of data objects.

Are there alternatives that would cause less memory usage?  In
S/S-PLUS the data.dump/data.restore functions use a portable
representation that can be parsed without exponential memory growth.
-- 
Douglas Bates                            bates@stat.wisc.edu
Statistics Department                    608/262-2598
University of Wisconsin - Madison        http://www.stat.wisc.edu/~bates/
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Representation of data in libraries
Douglas Bates