simple_sparse_array {slam}R Documentation

Simple Sparse Arrays

Description

Data structures and operators for sparse arrays based on a representation by index matrix and value vector.

Usage

simple_sparse_array(i, v, dim = NULL, dimnames = NULL)

as.simple_sparse_array(x)
is.simple_sparse_array(x)

Arguments

i

Integer matrix of array indices.

v

Vector of values.

dim

Integer vector specifying the size of the dimensions.

dimnames

either NULL or the names for the dimensions. This is a list with one component for each dimension, either NULL or a character vector of the length given by dim for that dimension. The list can be named, and the list names will be used as names for the dimensions. If the list is shorter than the number of dimensions, it is extended by NULL's to the length required.

x

An R object.

Details

simple_sparse_array is a generator for a class of “lightweight” sparse arrays, represented by index matrices and value vectors. Currently, only methods for indexing and coercion are implemented.

See Also

simple_sparse_array for sparse arrays.

Examples

x <- array(c(1, 0, 0, 2, 0, 0, 0, 3), dim = c(2, 2, 2))
s <- as.simple_sparse_array(x)
identical(x, as.array(s))

simple_sparse_array(matrix(c(1, 1, 1, 3, 3, 3), nrow = 2), c(1, 2))

[Package slam version 0.1-23 Index]