用途：用向量(稀疏存储)形式的Gauss-Seidel迭代解线性方程组Ax=b

％ 格式: x=spgs(A,b，x0,e,N),A为系数矩阵，b为右端向量，x返回解向量。

％ x0为初值向量(默认原点)，e为精度(默认1e-4),设置迭代次数上限以防发散(默

％ 认500)。 -purposes : with Vector (sparse storage) form of Gauss - Seidel iterative solution of linear equations Ax = b% Format : spgs x = (A, b, x0, e, N), A coefficient matrix, b subguadratic vector, returning x vector. X0% for initial vector (the default origin), e-precision (default 1e-4), iteration ceiling set to prevent divergence (mime identified 500%).