Quarter

共轭梯度法（Conjugate Gradient）是介于最速下降法与牛顿法之间的一个方法，它仅需利用一阶导数信息，但克服了最速下降法收敛慢的缺点，又避免了牛顿法需要存储和计算Hesse矩阵并求逆的缺点，共轭梯度法不仅是解决大型线性方程组最有用的方法之一，也是解大型非线性最优化最有效的算法之一(Conjugate gradient method (Conjugate Gradient) is between the steepest descent method and Newton' s method between a method that takes only a first derivative information, but to overcome the slow convergence of the steepest descent method shortcomings, but also avoid the need to store Newton and computing the inverse Hesse matrix and disadvantages, conjugate gradient method is not only to solve large linear equations of the most useful methods, large-scale nonlinear optimization solution is the most efficient algorithms)

共轭梯度法，本算法是经过验证了的共轭梯度法，读者在运用到其他方面时需要修改一定的参数(Conjugate gradient method, this algorithm is verified of the conjugate gradient method, readers in the use of other aspects need to modify certain parameters)

求非线性系统的相平面轨迹、平衡点时，编写采用一步仿真计算状态轨线斜率的函数M文件(Phase plane trajectory of nonlinear systems, the equilibrium point, write step simulation state rail line slope function M)

求解非线性不动点方程组x=G(x)的非线性塞德尔迭代方法，初值x0(For solving nonlinear fixed point equation x = G (x) the nonlinear Seidel iterative method, initial value x0)

说明：  本程序计算的太阳角有地面点对应的太阳天顶角和太阳方位角，太阳高度角与太阳天顶角 互余，所以太阳高度角也可以通过90 度-太阳天顶角计算得到(The solar angle is calculated by the solar zenith angle and the sun azimuth angle corresponding to the earth's surface point. The sun height angle and the sun zenith angle are complementary, so the sun height angle can also be calculated by the 90 degree sun zenith angle.)

程序设计的一些基本算法 及其应用 有很高的应用价值(Some basic programming algorithm and its application has a high value)

说明：  自己编的，实现l-bfgs解无约束优化问题(Own, and the realization of l-bfgs Unconstrained optimization problems)

说明：  解大规模线性方程组的预条件Gmres方法.系数矩阵可以非对称正定.(Solution of large-scale linear equations of the preconditioned GMRES method. Coefficient matrix can be non-symmetric positive definite.)

说明：  关联维数求解，大组件构建，可以快速得到关联维数的值。(The value of correlation dimension can be obtained quickly by solving the correlation dimension and constructing large components.)

线弹性模型，可以对一般的弹性体通过abaqus进行验证使用(Linear elastic model)