simple-squiggle/node_modules/mathjs/lib/cjs/function/algebra/solver/lusolve.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createLusolve = void 0;

var _is = require("../../../utils/is.js");

var _factory = require("../../../utils/factory.js");

var _solveValidation = require("./utils/solveValidation.js");

var _csIpvec = require("../sparse/csIpvec.js");

var name = 'lusolve';
var dependencies = ['typed', 'matrix', 'lup', 'slu', 'usolve', 'lsolve', 'DenseMatrix'];
var createLusolve = /* #__PURE__ */(0, _factory.factory)(name, dependencies, function (_ref) {
  var typed = _ref.typed,
      matrix = _ref.matrix,
      lup = _ref.lup,
      slu = _ref.slu,
      usolve = _ref.usolve,
      lsolve = _ref.lsolve,
      DenseMatrix = _ref.DenseMatrix;
  var solveValidation = (0, _solveValidation.createSolveValidation)({
    DenseMatrix: DenseMatrix
  });
  /**
   * Solves the linear system `A * x = b` where `A` is an [n x n] matrix and `b` is a [n] column vector.
   *
   * Syntax:
   *
   *    math.lusolve(A, b)     // returns column vector with the solution to the linear system A * x = b
   *    math.lusolve(lup, b)   // returns column vector with the solution to the linear system A * x = b, lup = math.lup(A)
   *
   * Examples:
   *
   *    const m = [[1, 0, 0, 0], [0, 2, 0, 0], [0, 0, 3, 0], [0, 0, 0, 4]]
   *
   *    const x = math.lusolve(m, [-1, -1, -1, -1])        // x = [[-1], [-0.5], [-1/3], [-0.25]]
   *
   *    const f = math.lup(m)
   *    const x1 = math.lusolve(f, [-1, -1, -1, -1])       // x1 = [[-1], [-0.5], [-1/3], [-0.25]]
   *    const x2 = math.lusolve(f, [1, 2, 1, -1])          // x2 = [[1], [1], [1/3], [-0.25]]
   *
   *    const a = [[-2, 3], [2, 1]]
   *    const b = [11, 9]
   *    const x = math.lusolve(a, b)  // [[2], [5]]
   *
   * See also:
   *
   *    lup, slu, lsolve, usolve
   *
   * @param {Matrix | Array | Object} A      Invertible Matrix or the Matrix LU decomposition
   * @param {Matrix | Array} b               Column Vector
   * @param {number} [order]                 The Symbolic Ordering and Analysis order, see slu for details. Matrix must be a SparseMatrix
   * @param {Number} [threshold]             Partial pivoting threshold (1 for partial pivoting), see slu for details. Matrix must be a SparseMatrix.
   *
   * @return {DenseMatrix | Array}           Column vector with the solution to the linear system A * x = b
   */

  return typed(name, {
    'Array, Array | Matrix': function ArrayArrayMatrix(a, b) {
      a = matrix(a);
      var d = lup(a);

      var x = _lusolve(d.L, d.U, d.p, null, b);

      return x.valueOf();
    },
    'DenseMatrix, Array | Matrix': function DenseMatrixArrayMatrix(a, b) {
      var d = lup(a);
      return _lusolve(d.L, d.U, d.p, null, b);
    },
    'SparseMatrix, Array | Matrix': function SparseMatrixArrayMatrix(a, b) {
      var d = lup(a);
      return _lusolve(d.L, d.U, d.p, null, b);
    },
    'SparseMatrix, Array | Matrix, number, number': function SparseMatrixArrayMatrixNumberNumber(a, b, order, threshold) {
      var d = slu(a, order, threshold);
      return _lusolve(d.L, d.U, d.p, d.q, b);
    },
    'Object, Array | Matrix': function ObjectArrayMatrix(d, b) {
      return _lusolve(d.L, d.U, d.p, d.q, b);
    }
  });

  function _toMatrix(a) {
    if ((0, _is.isMatrix)(a)) {
      return a;
    }

    if ((0, _is.isArray)(a)) {
      return matrix(a);
    }

    throw new TypeError('Invalid Matrix LU decomposition');
  }

  function _lusolve(l, u, p, q, b) {
    // verify decomposition
    l = _toMatrix(l);
    u = _toMatrix(u); // apply row permutations if needed (b is a DenseMatrix)

    if (p) {
      b = solveValidation(l, b, true);
      b._data = (0, _csIpvec.csIpvec)(p, b._data);
    } // use forward substitution to resolve L * y = b


    var y = lsolve(l, b); // use backward substitution to resolve U * x = y

    var x = usolve(u, y); // apply column permutations if needed (x is a DenseMatrix)

    if (q) {
      x._data = (0, _csIpvec.csIpvec)(q, x._data);
    }

    return x;
  }
});
exports.createLusolve = createLusolve;