兰 溪, 孙玉祥
(1.吉林油田第十一中学,吉林松原 138000; 2.北华大学师范学院数学系代数教研室,吉林 132013)
非奇异H-矩阵的实用判定
兰 溪1, 孙玉祥2
(1.吉林油田第十一中学,吉林松原 138000; 2.北华大学师范学院数学系代数教研室,吉林 132013)
H-矩阵在许多领域中都起着非常重要的作用,例如数学分析、矩阵理论、数学经济学、控制论等.但是在实际运用中判定H-矩阵却十分困难.本文类似于文[4],均以α-对角占优理论为基础,给出H-矩阵的若干实用判定,改进了文[3]的相应结果.
非奇异H-矩阵;广义严格对角占优矩阵;广义严格α-对角占优矩阵
众所周知,广义严格对角占优矩阵就是非奇异H-矩阵.因非奇异H-矩阵主对角元素非零,所以本文假定所涉及矩阵主对角元非零,设A=(aij)∈n×n为n阶复方阵,N={1,2,…,n}.设A的比较矩阵M(A)=(mij)∈R Rn×n为n阶实方阵,其中
则称为严格对角占优矩阵,记为A∈D.若存在一组正数di(i=1,2,…,n),使得
则称A为广义严格对角占优矩阵,记为A∈H.
定义2 设A=(aij)∈n×n,若存在α∈(0,1),使∀i∈N N,有
则称A为严格α-对角占优矩阵,记A∈D(α).若存在一组正数di(i=1,2,…,n),使
则称A为广义严格α-对角占优矩阵,记为A∈D*(α).
引理1[1]设A=(aij)∈n×n,则A是广义严格对角占优矩阵当且仅当A是广义严格α-对角占优矩阵.
引理2[2]设A=(aij)∈n×n,B=M(A)+MT(A).若B是广义严格对角占优矩阵,则A是广义严格对角占优矩阵.
定理设A=(aij)∈C Cn×n.若存在α∈(0,1),使
则B为广义严格α-对角占优矩阵,由引理1知B为广义严格对角占优矩阵,再由引理2知A∈H.
有了上述定理我们就很容易判定高阶矩阵是否为非奇异H-矩阵.看下面的例子:
[1] Sun Yu-Xiang.An improvement on a theorem by Ostrowski and its applications[J].North-eastern Math,1991,7(4):497-502.
[2] Berman A and Plemmons R J.Nonnegative matrices in the mathematical sciences[M].New York:Academic,1979.
[3] 徐仲,陆全.判定广义严格对角占优矩阵的一组充分条件[J].工程数学学报,2001,18(3):11-15.
[4] 谢清明.判定广义对角占优矩阵的几个充分条件[J].工程数学学报,2006,23(4):757-760.
Practical Criterion for Nonsingular H-Matrices
LAN Xi1, SUN Yu-xiang2
(1.No.11 Senior Middle School of Jilin Oil Field,Songyuan,Jilin 138000,China;
2.Department of Mathematics,Normal Science College,Beihua University,Jilin 132013,China)
H-matrices play a very important role in many fields like Numerical Analysis,Matrix theory,Mathematical Economics,Control theory,etc.But it is difficult to judge H-matrices in practice.In this paper,we give some practical criterions for nonsingular H-matrices abase on the theory ofα-diagonally dominant matrices,it is similar to[4].And improve the results of[3].
nonsingular H-matrices;generalized strictly diagonally dominant matrix;generalized strictlyα-diagonally dominant matrix
O151.21
A
1672-1454(2010)05-0109-03
2008-06-16