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