用cholesky法解最小二乘法，矩阵三角分解-Cholesky method for the least squares method, the matrix triangular decomposition

各种常见的解方程组方法：Cholesky分解法解方程组、LU分解线性方程组、高斯消去法解方程组、列主元解线性方程组、雅可比迭代解线性方程组-Common solution of equations: the Cholesky decomposition of equations, LU decomposition of linear equations, Gaussian elimination method for solving equations, column element for s