R: Sparsity

sparsity {coop} | R Documentation

## Sparsity

### Description

Show the sparsity (as a count or proportion) of a matrix. For example, .99 sparsity means 99% of the values are zero. Similarly, a sparsity of 0 means the matrix is fully dense.

### Usage

    sparsity(x, proportion = TRUE)

### Arguments

`x` | The matrix, stored as an ordinary R matrix or as a "simple triplet matrix" (from the slam package).
`proportion` | Logical; should a proportion or a count be returned?

### Details

The implementation is very efficient for dense matrices. For sparse triplet matrices, the count is trivial.

### Value

The sparsity of the input matrix, as a proportion or a count.

### Author(s)

Drew Schmidt

### Examples

    ## Completely sparse matrix
    x <- matrix(0, 10, 10)
    coop::sparsity(x)

    ## 15\% density / 85\% sparsity
    x[sample(length(x), size=15)] <- 1
    coop::sparsity(x)

[Package coop version 0.6-2 Index]