vendor/phpoffice/phpexcel/Classes/PHPExcel/Shared/JAMA/LUDecomposition.php

这里只显示每个文件的开头 60 行。登录后可以解锁完整代码。

微信扫码关注公众号，代码整理好后第一时间通知你。

<?php
/**
 *	@package JAMA
 *
 *	For an m-by-n matrix A with m >= n, the LU decomposition is an m-by-n
 *	unit lower triangular matrix L, an n-by-n upper triangular matrix U,
 *	and a permutation vector piv of length m so that A(piv,:) = L*U.
 *	If m < n, then L is m-by-m and U is m-by-n.
 *
 *	The LU decompostion with pivoting always exists, even if the matrix is
 *	singular, so the constructor will never fail. The primary use of the
 *	LU decomposition is in the solution of square systems of simultaneous
 *	linear equations. This will fail if isNonsingular() returns false.
 *
 *	@author Paul Meagher
 *	@author Bartosz Matosiuk
 *	@author Michael Bommarito
 *	@version 1.1
 *	@license PHP v3.0
 */
class PHPExcel_Shared_JAMA_LUDecomposition {

	const MatrixSingularException	= "Can only perform operation on singular matrix.";
	const MatrixSquareException		= "Mismatched Row dimension";

	/**
	 *	Decomposition storage
	 *	@var array
	 */
	private $LU = array();

	/**
	 *	Row dimension.
	 *	@var int
	 */
	private $m;

	/**
	 *	Column dimension.
	 *	@var int
	 */
	private $n;

	/**
	 *	Pivot sign.
	 *	@var int
	 */
	private $pivsign;

	/**
	 *	Internal storage of pivot vector.
	 *	@var array
	 */
	private $piv = array();


	/**
	 *	LU Decomposition constructor.
	 *
	 *	@param $A Rectangular matrix