Preconditioned con- jugate gradient algorithm is a fast and accurate computational algorithm.

预条件共轭梯度法是一种精确并且收敛迅速的计算方法。

The trackability limitation of current gradient algorithm is discussed.A new algorithm, named variable parameter gradient estimation algorithm with local polynomial approximation is proposed.

本文分析了梯度辨识算法跟踪时变系统的缺点，提出了一种新的基于局部多项式逼近的变参数梯度估计算法。

Image reconstruction is often converted to the nonrestraint extremum of the nonlinear equations.We have deduced a conjugate gradient algorithm from the extremum of norm.

图像重建常常被转化为解非线性无约束极值问题,通过范数极小化推导出共轭梯度法的一般算法。