中文说明： MINRES、PCG算法可提供收敛性十分好的矩阵计算方法，给出了MINRES、PCG算法的完整matlab函数。使用者可以通过它获得矩阵方程的解，以及每一步迭代所得到的残差。对残差作图，可以清晰的得到残差图像结果。
English Description：
MINRES, PCG algorithm convergence provides a very good way of matrix computations, MINRES, PCG algorithm is given the full MATLAB functions. Users can use it to obtain solution of a matrix equation, and each iteration the residuals received. Residual mapping, and can get the residual image results.