# cosine: Cosine Similarity In coop: Co-Operation: Fast Covariance, Correlation, and Cosine Similarity Operations

## Description

Compute the cosine similarity matrix efficiently. The function syntax and behavior is largely modeled after that of the cosine() function from the lsa package, although with a very different implementation.

## Usage

 1 2 3 cosine(x, y, use = "everything", inverse = FALSE) tcosine(x, y, use = "everything", inverse = FALSE) 

## Arguments

 x A numeric dataframe/matrix or vector. y A vector (when x is a vector) or missing (blank) when x is a matrix. use The NA handler, as in R's cov() and cor() functions. Options are "everything", "all.obs", and "complete.obs". inverse Logical; should the inverse covariance matrix be returned?

## Details

See ?coop-package for implementation details.

## Value

The n\times n matrix of all pair-wise vector cosine similarities of the columns.

## Author(s)

Drew Schmidt

sparsity
 1 2 3 4 x <- matrix(rnorm(10*3), 10, 3) coop::cosine(x) coop::cosine(x[, 1], x[, 2])