Data Frames Stored on Disk

Description

The matter_df class implements on-disk data frames.

Usage

## Instance creation
matter_df(..., row.names = NULL)

## Additional methods documented below

Arguments

Value

An object of class matter_df.

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 is 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_df instances can be created through matter_df() or matter().

Methods

Standard generic methods:

x$name, x$name <- value:

Get or set the data columns.

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

Get or set the data columns.

x[i, j, ..., drop], x[i, j] <- value:

Get or set the elements of the data frame.

Author(s)

Kylie A. Bemis

See Also

matter

Examples

x <- matter_df(a=as.matter(1:10), b=as.matter(1:10))
x[]
x[[1]]
x[["a"]]
x[,"a"]
x[1:5,c("a","b")]
x$a
x$a[1:10]