彭 凌,莫宏敏
(吉首大學(xué)數(shù)學(xué)與統(tǒng)計(jì)學(xué)院,湖南 吉首 416000)
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雙α-鏈對(duì)角占優(yōu)矩陣線性互補(bǔ)問題的誤差界
彭凌,莫宏敏
(吉首大學(xué)數(shù)學(xué)與統(tǒng)計(jì)學(xué)院,湖南 吉首 416000)
摘要:根據(jù)雙α-鏈對(duì)角占優(yōu)矩陣的定義與性質(zhì),給出其線性互補(bǔ)問題的誤差界.數(shù)值實(shí)例顯示該誤差界在判定線性互補(bǔ)問題近似解的精確性中是有效的.
關(guān)鍵詞:精確性;誤差界;線性互補(bǔ)問題;雙α-鏈對(duì)角占優(yōu)矩陣
雙α-鏈對(duì)角占優(yōu)矩陣在數(shù)學(xué)、物理、控制論以及經(jīng)濟(jì)學(xué)等許多領(lǐng)域有重要作用.雙α-鏈對(duì)角占優(yōu)矩陣也是非奇異H-矩陣,是一類范圍很廣的特殊矩陣,特別是關(guān)于雙α-鏈對(duì)角占優(yōu)矩陣的線性互補(bǔ)問題,也是數(shù)學(xué)規(guī)劃中與凸二次規(guī)劃密切相關(guān)的重要問題.近年來(lái),國(guó)內(nèi)外許多學(xué)者研究了多類特殊矩陣線性互補(bǔ)問題的誤差界,取得了一些成果[1-3].筆者將根據(jù)雙α-鏈對(duì)角占優(yōu)矩陣的定義與性質(zhì),在文獻(xiàn)[4]的基礎(chǔ)上對(duì)其誤差界進(jìn)行改進(jìn),得到關(guān)于雙α-鏈對(duì)角占優(yōu)矩陣線性互補(bǔ)問題的新的誤差界,并應(yīng)用實(shí)例進(jìn)行驗(yàn)證.
1預(yù)備知識(shí)
線性互補(bǔ)問題是指:存在一向量x∈Rn,使得
Mx+q≥0,x≥0,xT(Mx+q)=0,
其中M是n×n矩陣,q∈Rn.將線性互補(bǔ)問題記作LCP(M,q),x*為L(zhǎng)CP(M,q)的解.
眾所周知,具有正對(duì)角元的H-矩陣是一個(gè)P-矩陣.
定義2[5]若存在α∈[0,1],使得?i≠j(i,j∈N),有
|aii||ajj|≥((Λi(A))α(Si(A))1-α)((Λj(A))α(Sj(A))1-α)
(1)
成立,則稱A是雙α-鏈對(duì)角占優(yōu)矩陣.
引理3若實(shí)矩陣A=(aij)∈Rn×n是雙α-鏈對(duì)角占優(yōu)矩陣,則存在正對(duì)角矩陣X=diag(x1,x2,…,xn),AX是嚴(yán)格對(duì)角占優(yōu)矩陣.其中:
(2)
取正對(duì)角矩陣X=(x1,x2,…,xn),當(dāng)i∈N1時(shí),xi=η,當(dāng)j∈N2時(shí),xj=1.令Q=AX=(qij),易證qii-Λi(Q)>0,i∈N,所以AX是嚴(yán)格對(duì)角占優(yōu)矩陣.
由引理1易知,若A=(aij)∈Rn×n是雙α-鏈對(duì)角占優(yōu)矩陣,則A是H-矩陣.
2主要結(jié)果及證明
考慮對(duì)角元素為正的雙α-鏈對(duì)角占優(yōu)矩陣M,易知M是P-矩陣.由文獻(xiàn)[1]定理2.3的第3個(gè)不等式,對(duì)?x∈Rn,有
其中:I是n×n單位矩陣;D是對(duì)角矩陣,D=diag(di),0≤di≤1,i=1,2,…,n;x*是LCP(M,q)的解;r(x)∶=min(x,Mx+q).由文獻(xiàn)[1]定理2.1可知,當(dāng)M=(aij)∈Cn×n是主對(duì)角元素為正的H-矩陣時(shí),
(3)
若η<1,則
證明由引理1知,MX是主對(duì)角元素為正的嚴(yán)格對(duì)角占優(yōu)矩陣.由文獻(xiàn)[6]中定理A易證,對(duì)?d∈[0,1]n,(I-D+DM)X也是主對(duì)角元素為正的嚴(yán)格對(duì)角占優(yōu)矩陣,于是
‖(I-D+DM)-1‖∞=‖X(X-DX+DMX)-1‖∞≤‖X‖∞‖(X-DX+DMX)-1‖∞≤
又因?yàn)?/p>
且i∈N2時(shí),xi=1,當(dāng)i∈N1時(shí),xi=η,所以當(dāng)η>1時(shí),
當(dāng)η<1時(shí),
3數(shù)值實(shí)例
參考文獻(xiàn):
[1] BERMAN A,PLEMMONS R J.Nonnegative Matrices in the Mathematical Science[M].New York:Academic Press,1979.
[2] CHEN Xiaojun,XIANG Shuhuang.Computation of Error Bounds forP-Matrix Linear Complementarity Problems[J].Math. Program. Ser. A,2006,106:513-525.
[3] CVETKOVIC L,KOSTIC V,VARGA R S.A New Gersgorin-Type Eigenvalue Inclusion Set[J].Electron. Trans. Numer. Anal.,2004,18:73-80.
[5] 汪祥,盧琳璋.α-雙對(duì)角占優(yōu)與H矩陣的判定[J].廈門大學(xué)學(xué)報(bào):自然科學(xué)版,2003,42(5):570-572.
[6] VARGA R S.On Diagonal Dominance Arguments for Bounding ‖A-1‖∞[J].Linear Algebra Appl.,1976,14:211-217.
(責(zé)任編輯向陽(yáng)潔)
On Error Bound for Linear Complementarity Problem of Double
α-Chain Diagonally Dominant Matrix
PENG Ling,MO Hongmin
(College of Mathematics and Statistics,Jishou University,Jishou 416000,Hunan China)
Abstract:In this paper,we give new error bound for the linear complementarity problem where the involved matrix is a doubleα-chain diagonally dominant matrix based on its definition and properties.Preliminary numerical results show that the proposed error bound is efficient for verifying accuracy of approximate solutions.
Key words:accuracy;error bound;linear complementarity problem;doubleα-chain diagonally dominant matrix
作者簡(jiǎn)介:彭凌(1982—),女,湖南懷化人,碩士研究生,主要從事矩陣?yán)碚撆c計(jì)算研究;莫宏敏(1969—),男,湖南慈利人,吉首大學(xué)數(shù)學(xué)與統(tǒng)計(jì)學(xué)院副教授,博士,主要從事矩陣?yán)碚撆c計(jì)算研究.
基金項(xiàng)目:吉首大學(xué)校級(jí)科研項(xiàng)目(13JDY043)
收稿日期:2014-11-09
中圖分類號(hào):O151.21
文獻(xiàn)標(biāo)志碼:A
DOI:10.3969/j.issn.1007-2985.2015.02.005
文章編號(hào):1007-2985(2015)02-0020-03