[,laf-method

[,laf_column-method

When a connection is opened to a <code>"laf"</code> object; this
object can then be indexed roughly as one would a <code>data.frame</code>.

Methods for fast access to large ASCII files.  Currently the
following file formats are supported: comma separated format (CSV) and fixed
width format. 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. Methods are provided to access and process files blockwise.
Furthermore, an opened file can be accessed as one would an ordinary
data.frame. The LaF vignette gives an overview of the functionality
provided.

Jan der Laan

Fast Access to Large ASCII Files

Jan van der Laan

[,laf-method function

<dl><dt>x</dt>
<dd>an object of type <code>"laf"</code> or
<code>"laf_column"</code>.</dd>
<dt>i</dt>
<dd>an logical or numeric vector with indices. The rows which should be
selected.</dd>
<dt>j</dt>
<dd>a numeric vector with the columns to select.</dd>
<dt>drop</dt>
<dd>a logical indicating whether or not to convert the result to a
vector when only one column is selected. As in when indexing a
<code>data.frame</code>.</dd></dl>

Arguments

Read records from a large file object into R — [,laf-method

<dl>

<dt>x</dt>
<dd>an object of type <code>"laf"</code> or
<code>"laf_column"</code>.</dd>


<dt>i</dt>
<dd>an logical or numeric vector with indices. The rows which should be
selected.</dd>


<dt>j</dt>
<dd>a numeric vector with the columns to select.</dd>


<dt>drop</dt>
<dd>a logical indicating whether or not to convert the result to a
vector when only one column is selected. As in when indexing a
<code>data.frame</code>.</dd>

</dl>

[,laf-method: Read records from a large file object into R

Description

Usage

Arguments