Binmat-class: On-Disk Matrix Class Using On-Demand Disk Reads

Description

The Binmat class implements on-disk matrices with efficient access to columns. Values within each column are contiguously stored in a binary file on disk. The columns themselves need not be stored contiguously. Only the accessed elements of the matrix are loaded into memory.

Usage

## Instance creation
Binmat( files, nrow, ncol, offsets = 0, extents = rep(nrow, ncol), datatype = c("16-bit integer", "32-bit integer", "64-bit integer", "32-bit float", "64-bit float"), dimnames = NULL, ...)
## Additional methods documented below

Arguments

files

The file(s) where the matrix is stored.

nrow

The number of rows in the on-disk matrix.

ncol

The number of columns in the on-disk matrix.

offsets

The positions of the first value of each column in number of bytes from the beginning of the file.

extents

The length of each column.

datatype

The binary data type.

dimnames

The 'dimnames' giving the dimension names for the matrix, analogous to the 'dimnames' attribute of an ordinary R matrix. This must be a list of length 2 or NULL.

...

Additional arguments passed to the constructor.

Slots

files:: A factor giving the full file paths of the binary files storing the matrix (or matrices) on disk. Length must be equal to the number of columns.
offsets:: A numeric vector giving the positions of the first value of each column in number of bytes from the beginning of the file.
extents:: A numeric vector giving the length of each column.
datatype:: A factor vector giving the binary data types of each element of the matrix (or matrices) on disk. Length must be equal to the number of columns.
dim:: A length 2 integer vector analogous to the 'dim' attribute of an ordinary R matrix.
dimnames:: A length 2 list analogous to the 'dimnames' attribute of an ordinary R matrix.
.__classVersion__:: A Versions object describing the version of the class used to created the instance. Intended for developer use.

Extends

Versioned

Creating Objects

Binmat instances are usually created through Binmat().

Methods

Standard generic methods:

dim(x), dim(x) <- value:: Return or set the dimensions of the on-disk matrix.
dimnames(x), dimnames(x) <- value:: Return or set the 'dimnames' of the on-disk matrix.
colnames(x), colnames(x) <- value:: Return or set the column names of the on-disk matrix.
rownames(x), rownames(x) <- value:: Return or set the row names of the on-disk matrix.
ncol:: Return the number of columns in the on-disk matrix.
nrow:: Return the number of columns in the on-disk matrix.
cbind:: Combine on-disk matrices by columns.
rbind:: Not allowed for on-disk matrices. (Always returns an error.)
Binmat[i, j, ..., drop]:: Access elements in the on-disk matrix. A Binmat on-disk matrix can be indexed like an ordinary R matrix. Note however that linear indexing is not supported. Assignment is not currently allowed.

Examples

Run this code

## Not run: 
# ## Create an Binmat object
# Binmat("path/to/file.extension")
# ## End(Not run)

Run the code above in your browser using DataLab