求解大规模对称矩阵的CG算法，及预处理PCG使用Matlab语言，可以解1000阶以上的矩阵，以病态矩阵hilbert为例,Solving large-scale symmetric matrix of the CG algorithm, and pretreatment of PCG using Matlab language, you can order more than 1,000 solution matrix, as an example to pathological matrix

利用共轭梯度法（CG+）求解大规模无约束最优化问题，代码所用语言为Fortran77.-The use of conjugate gradient method (CG+) to solve large-scale unconstrained optimization problems, the code language for Fortran77.

曲线拟合问题用C语言编写最小二乘法CG方法与QR方法，其中CG方法两种-The method of least squares curve fitting problems using the C language CG method and QR method, in which both CG method