[R-pkgs] LaF 0.3: fast access to large ASCII files

From: Jan van der Laan <djvanderlaan_at_unrealizedtime.nl>
Date: Sun, 13 Nov 2011 13:42:36 +0100


The LaF package provides methods for fast access to large ASCII files. Currently the following file formats are supported:

It is assumed that the files are too large to fit into memory, although the package can also be used to efficiently access files that do fit into memory.

In order to process files that are too large to fit into memory, methods are provided to access and process file blockwise. Furthermore, an opened file can be indexed as one would a data.frame. In this way subsets. or specific columns can be read into memory. For example, assuming that an object laf has been created using one of the functions laf_open_csv or laf_open_fwf, the third column from the file can be read into memory using:

> col <- laf[,3]

The LaF-manual vignette contains a description of all functionality provided:

   http://laf-r.googlecode.com/files/LaF-manual_0.3.pdf

The Laf-benchmark vignette compares the performance of LaF to the standard R-routines read.table and read.fwf:

   http://laf-r.googlecode.com/files/LaF-benchmark_0.3.pdf



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