matter_arr-class {matter}R Documentation

Arrays Stored on Disk

Description

The matter_arr class implements on-disk arrays.

Usage

## Instance creation
matter_arr(data, datamode = "double", paths = NULL,
            filemode = ifelse(all(file.exists(paths)), "rb", "rb+"),
            offset = 0, extent = prod(dim), dim = 0, dimnames = NULL, ...)

## Additional methods documented below

Arguments

data

An optional data vector which will be initially written to the data on disk if provided.

datamode

A 'character' vector giving the storage mode of the data on disk. Allowable values are the C types ('char', 'uchar', short', 'ushort', 'int', 'uint', 'long', 'ulong', 'float') and their R equivalents ('raw', 'logical', 'integer', 'numeric').

paths

A 'character' vector of the paths to the files where the data are stored. If 'NULL', then a temporary file is created using tempfile.

filemode

The read/write mode of the files where the data are stored. This should be 'rb' for read-only access, or 'rb+' for read/write access.

offset

A vector giving the offsets in number of bytes from the beginning of each file in 'paths', specifying the start of the data to be accessed for each file.

extent

A vector giving the length of the data for each file in 'paths', specifying the number of elements of size 'datamode' to be accessed from each file.

dim

A vector giving the dimensions of the array.

dimnames

The names of the matrix dimensions.

...

Additional arguments to be passed to constructor.

Value

An object of class matter_arr.

Slots

data:

This slot stores the information about locations of the data on disk and within the files.

datamode:

The storage mode of the accessed data when read into R. This should a 'character' vector of length one with value 'integer' or 'numeric'.

paths:

A 'character' vector of the paths to the files where the data are stored.

filemode:

The read/write mode of the files where the data are stored. This should be 'rb' for read-only access, or 'rb+' for read/write access.

chunksize:

The maximum number of elements which should be loaded into memory at once. Used by methods implementing summary statistics and linear algebra. Ignored when explicitly subsetting the dataset.

length:

The length of the data.

dim:

Either 'NULL' for vectors, or an integer vector of length one of more giving the maximal indices in each dimension for matrices and arrays.

names:

The names of the data elements for vectors.

dimnames:

Either 'NULL' or the names for the dimensions. If not 'NULL', then this should be a list of character vectors of the length given by 'dim' for each dimension. This is always 'NULL' for vectors.

ops:

Delayed operations to be applied on atoms.

Extends

matter

Creating Objects

matter_arr instances can be created through matter_arr() or matter().

Methods

Standard generic methods:

x[...], x[...] <- value:

Get or set the elements of the array.

Author(s)

Kylie A. Bemis

See Also

matter

Examples

x <- matter_arr(1:125, dim=c(5,5,5))
x[]

[Package matter version 1.8.3 Index]