摘要
本文用高阶近似LU分解作预处理阵,对不同算例作点PCG数值计算,同时也用高阶近似求逆法作块近似LU分解,对同样算例作块PCG数值计算。结果表明点PCG在绝大部分算例中具有比同阶的块PCG较高的收敛速率,其因子分解计算量加上迭代求解计算量小于同阶块PCG的计算量,从而论证了当阶相同时,P阶近似LU分解的点PCG法比P阶近似逆阵的块PCG法计算效率高。
Using the method of the element order in matrices, high order approximate LU decompositions are used as the preconditioners for the computation of different experiments. Highorder approximate inverses are also adopted for the approximate block LU decomposition in the computation of the block-PCG for same experiments. The results show that the point -PCG of order P has a higher convergence rate than the block-PCG of order P when P = 2.3,…, 6. The total computational cost of the point-PCG is less than the block-PCG of the same order. This illustates that the point-PCG of the P-order approximate LU decomposition is more efficient than the block -PCG of the P -order approximate inverse when the order P varies in the scope considered.
出处
《计算物理》
CSCD
北大核心
1990年第4期407-414,共8页
Chinese Journal of Computational Physics
基金
国家自然科学基金
