import { isInteger } from '../../../utils/number.js'; import { factory } from '../../../utils/factory.js'; import { createCsSqr } from '../sparse/csSqr.js'; import { createCsLu } from '../sparse/csLu.js'; var name = 'slu'; var dependencies = ['typed', 'abs', 'add', 'multiply', 'transpose', 'divideScalar', 'subtract', 'larger', 'largerEq', 'SparseMatrix']; export var createSlu = /* #__PURE__ */factory(name, dependencies, _ref => { var { typed, abs, add, multiply, transpose, divideScalar, subtract, larger, largerEq, SparseMatrix } = _ref; var csSqr = createCsSqr({ add, multiply, transpose }); var csLu = createCsLu({ abs, divideScalar, multiply, subtract, larger, largerEq, SparseMatrix }); /** * Calculate the Sparse Matrix LU decomposition with full pivoting. Sparse Matrix `A` is decomposed in two matrices (`L`, `U`) and two permutation vectors (`pinv`, `q`) where * * `P * A * Q = L * U` * * Syntax: * * math.slu(A, order, threshold) * * Examples: * * const A = math.sparse([[4,3], [6, 3]]) * math.slu(A, 1, 0.001) * // returns: * // { * // L: [[1, 0], [1.5, 1]] * // U: [[4, 3], [0, -1.5]] * // p: [0, 1] * // q: [0, 1] * // } * * See also: * * lup, lsolve, usolve, lusolve * * @param {SparseMatrix} A A two dimensional sparse matrix for which to get the LU decomposition. * @param {Number} order The Symbolic Ordering and Analysis order: * 0 - Natural ordering, no permutation vector q is returned * 1 - Matrix must be square, symbolic ordering and analisis is performed on M = A + A' * 2 - Symbolic ordering and analisis is performed on M = A' * A. Dense columns from A' are dropped, A recreated from A'. * This is appropriatefor LU factorization of unsymmetric matrices. * 3 - Symbolic ordering and analisis is performed on M = A' * A. This is best used for LU factorization is matrix M has no dense rows. * A dense row is a row with more than 10*sqr(columns) entries. * @param {Number} threshold Partial pivoting threshold (1 for partial pivoting) * * @return {Object} The lower triangular matrix, the upper triangular matrix and the permutation vectors. */ return typed(name, { 'SparseMatrix, number, number': function SparseMatrixNumberNumber(a, order, threshold) { // verify order if (!isInteger(order) || order < 0 || order > 3) { throw new Error('Symbolic Ordering and Analysis order must be an integer number in the interval [0, 3]'); } // verify threshold if (threshold < 0 || threshold > 1) { throw new Error('Partial pivoting threshold must be a number from 0 to 1'); } // perform symbolic ordering and analysis var s = csSqr(order, a, false); // perform lu decomposition var f = csLu(a, s, threshold); // return decomposition return { L: f.L, U: f.U, p: f.pinv, q: s.q, toString: function toString() { return 'L: ' + this.L.toString() + '\nU: ' + this.U.toString() + '\np: ' + this.p.toString() + (this.q ? '\nq: ' + this.q.toString() : '') + '\n'; } }; } }); });