机构地区: 汕头大学理学院数学系
出 处: 《中山大学学报论丛》 1996年第5期29-32,共4页
摘 要: 基于区域分解和多项式插值,对积分算子进行离散,得到高精确度的近似离散矩阵.这一方法适应于核函数为光滑、振动较小、只有有限弱奇点的情形.如果采用n个离散点,近似矩阵可以经过O(n)次计算得到,存储也只要O(n).矩阵-向量相乘的计算量为O(nlogn).所以。 Based on polynomial interpolation, we present a fast algorithm to approximate matrices arising from the discretization of second kind integral equations where the kernel function is either smooth, non oscillatory and possessing only a finite number of singularities. The approximation can be constructed in O(n) operations and requires O(n) storage, where n is the number of quadrature points used in the discretization. Moreover, the matrix vector multiplication cost is of order O(n log n). Thus our scheme is well suitable for conjugate gradient type methods.