[.MVL_OBJECT

Retrieve objects stored in mappable vector library. Large nested objects are returned as instances of MVL_OBJECT to delay access until needed.

Mappable vector library provides convenient way to access large datasets. Use all of your data at once, with few limits. Memory mapped data can be shared between multiple R processes. Access speed depends on storage medium, so solid state drive is recommended, preferably with PCI Express (or M.2 nvme) interface or a fast network file system. The data is memory mapped into R and then accessed using usual R list and array subscription operators. Convenience functions are provided for merging, grouping and indexing large vectors and data.frames. The layout of underlying MVL files is optimized for large datasets. The vectors are stored to guarantee alignment for vector intrinsics after memory map. The package is built on top of libMVL, which can be used as a standalone C library. libMVL has simple C API making it easy to interchange datasets with outside programs. Large MVL datasets are distributed via Academic Torrents <https://academictorrents.com/collection/mvl-datasets>.

Vladimir Dergachev

RMVL

Mappable Vector Library for Handling Large Datasets

[.MVL_OBJECT function

<dl><dt>obj</dt>
<dd>- MVL object retrieved by subscription of MVL library or other objects</dd>
<dt>i</dt>
<dd>- optional index.</dd>
<dt>drop</dt>
<dd>- whether to drop dimensionality, such as done with R array or data frames</dd>
<dt>raw</dt>
<dd>- request to return data in raw format when it does not map exactly to R data types.</dd>
<dt>recurse</dt>
<dd>- force recursive conversion to pure R objects.</dd>
<dt>ref</dt>
<dd>- always return an MVL_OBJECT</dd>
<dt>...</dt>
<dd>optional additional indices for multidimensional arrays and data frames</dd></dl>

Arguments

MVL object subscription operator — [.MVL_OBJECT

<dl>

<dt>obj</dt>
<dd>- MVL object retrieved by subscription of MVL library or other objects</dd>


<dt>i</dt>
<dd>- optional index.</dd>


<dt>drop</dt>
<dd>- whether to drop dimensionality, such as done with R array or data frames</dd>


<dt>raw</dt>
<dd>- request to return data in raw format when it does not map exactly to R data types.</dd>


<dt>recurse</dt>
<dd>- force recursive conversion to pure R objects.</dd>


<dt>ref</dt>
<dd>- always return an MVL_OBJECT</dd>


<dt>...</dt>
<dd>optional additional indices for multidimensional arrays and data frames</dd>

</dl>

[.MVL_OBJECT: MVL object subscription operator

Description

Usage

Value

Arguments

Details