A very minimal incremental compressed sparse row matrix library for JavaScript.
npm i csr-matrix
var dict = {}
dict[[1,2]] = 1
dict[[0,0]] = 2.5
dict[[3,4]] = 5
var CSRMatrix = require("csr-matrix")
var M = CSRMatrix.fromDictionary(dict, 4, 5)
console.log(M.apply([1,2,3,4,5], []))
CSRMatrices are optimized for exactly one thing: fast matrix-vector multiplies. The way you do this is by calling the following method:
There are several ways to create csr-matrices. The most direct way to do this is to just call the constructor yourself:
CSRMatrix.fromList(items[, nrows, ncols])
Turns an array of entries of the form [row, column, value]
into a sparse matrix. Note that if there are some zero rows or columns at the end of the matrix, you need to specify the number of rows/columns in the optional nrows/ncols arguments.
CSRMatrix.fromDictionary(dict[, nrows, ncols])
Converts a JavaScript object with entries for the form "row,column"
into a sparse matrix.
CSRMatrix.fromDense(mat)
Turns an array-of-arrays into a csr matrix
CSRMatrix.fromNDArray(ndarr)
Turns a 2D dimensional ndarray into a csr matrix
matrix.apply(vector[, result])
This computes the normal matrix-vector product, but is often much faster than a dense multiply since the matrix is stored in a compressed sparse format.
vector
is the vector to be multipliedresult
is an optional array which gets the result. If not specified, a new vector gets allocatedReturns the resulting product
matrix.transpose()
Returns the transpose of the matrix
matrix.rowCount
Returns the number of rows
matrix.columnCount
Returns the number of columns
matrix.toList()
Converts matrix into a list format
matrix.toDictionary()
Converts matrix into hash table
matrix.toDense()
Converts matrix into array of arrays
matrix.toNDArray(out)
Converts matrix into ndarray
out
is the output ndarray(c) 2013-2015 Mikola Lysenko. BSD