import { arraySize as size } from '../../utils/array.js'; import { factory } from '../../utils/factory.js'; var name = 'kron'; var dependencies = ['typed', 'matrix', 'multiplyScalar']; export var createKron = /* #__PURE__ */factory(name, dependencies, _ref => { var { typed, matrix, multiplyScalar } = _ref; /** * Calculates the kronecker product of 2 matrices or vectors. * * NOTE: If a one dimensional vector / matrix is given, it will be * wrapped so its two dimensions. * See the examples. * * Syntax: * * math.kron(x, y) * * Examples: * * math.kron([[1, 0], [0, 1]], [[1, 2], [3, 4]]) * // returns [ [ 1, 2, 0, 0 ], [ 3, 4, 0, 0 ], [ 0, 0, 1, 2 ], [ 0, 0, 3, 4 ] ] * * math.kron([1,1], [2,3,4]) * // returns [ [ 2, 3, 4, 2, 3, 4 ] ] * * See also: * * multiply, dot, cross * * @param {Array | Matrix} x First vector * @param {Array | Matrix} y Second vector * @return {Array | Matrix} Returns the kronecker product of `x` and `y` */ return typed(name, { 'Matrix, Matrix': function MatrixMatrix(x, y) { return matrix(_kron(x.toArray(), y.toArray())); }, 'Matrix, Array': function MatrixArray(x, y) { return matrix(_kron(x.toArray(), y)); }, 'Array, Matrix': function ArrayMatrix(x, y) { return matrix(_kron(x, y.toArray())); }, 'Array, Array': _kron }); /** * Calculate the kronecker product of two matrices / vectors * @param {Array} a First vector * @param {Array} b Second vector * @returns {Array} Returns the kronecker product of x and y * @private */ function _kron(a, b) { // Deal with the dimensions of the matricies. if (size(a).length === 1) { // Wrap it in a 2D Matrix a = [a]; } if (size(b).length === 1) { // Wrap it in a 2D Matrix b = [b]; } if (size(a).length > 2 || size(b).length > 2) { throw new RangeError('Vectors with dimensions greater then 2 are not supported expected ' + '(Size x = ' + JSON.stringify(a.length) + ', y = ' + JSON.stringify(b.length) + ')'); } var t = []; var r = []; return a.map(function (a) { return b.map(function (b) { r = []; t.push(r); return a.map(function (y) { return b.map(function (x) { return r.push(multiplyScalar(y, x)); }); }); }); }) && t; } });