🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Article View: sci.math.num-analysis
Article #1290

how to solve a linear system of eqs.

#1290
From: jtrsmith
Date: Fri, 30 Sep 1994 16:22
30 lines
1935 bytes
I have a system of linear eqs and find it difficult to get a solution:

     (Diag(a)*E -Diag(Ea)) X = b
     trace(X) = 0 

  where a and b are n-dimensional vectors, E is a NxN symmetric matrix.
a, b, E are given.

(Note: only N eqs. of the above are linear independent. It's know that
 trace(b) = 0 which makes sure that the system has a unique solution)

Could anyone help me to solve it? Thanks.

George Cheng.
(If possible, please respond to my account)
-----------------------------------
if N=2, then the solution is:
     X =-D  b
      1   12 1
 
     X =-D  b
      2   21 2

  where D  = 1/E
         ij     ij
-----------------------------------
(   trace(X) here means the sum of all elements of vector X,
    Diag(X) means a diagonal matrix with the elements of X as the
diagonal elements of the matrix)
Technical Details
Message-ID: <36hdva$5g1@agate.berkeley.edu>
Path: arc1-ca.pugleaf.net!bga.com!news.sprintlink.net!howland.reston.ans.net!agate!garnet.berkeley.edu!jtrsmith

Show Full Headers
Complete Article Headers
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 10c033,b25c9c09da2e3635,start
X-Google-Attributes: gid10c033,public
X-Google-Thread: 107079,b25c9c09da2e3635,start
X-Google-Attributes: gid107079,public
X-Google-Thread: 109d8a,b25c9c09da2e3635,start
X-Google-Attributes: gid109d8a,public
X-Google-Thread: fad1e,b25c9c09da2e3635,start
X-Google-Attributes: gidfad1e,public
X-Google-Thread: 104d16,b25c9c09da2e3635,start
X-Google-Attributes: gid104d16,public
X-Google-Thread: f4956,b25c9c09da2e3635,start
X-Google-Attributes: gidf4956,public
X-Google-ArrivalTime: 1994-10-01 04:53:05 PST
Path: arc1-ca.pugleaf.net!bga.com!news.sprintlink.net!howland.reston.ans.net!agate!garnet.berkeley.edu!jtrsmith
From: jtrsmith@garnet.berkeley.edu ()
Newsgroups: sci.math.num-analysis,sci.math,sci.math.symbolic,ucb.math,fj.sci.math,ucb.math.seminars
Subject: how to solve a linear system of eqs.
Date: 30 Sep 1994 16:22:02 GMT
Organization: University of California, Berkeley
Lines: 30
Distribution: inet
Message-ID: <36hdva$5g1@agate.berkeley.edu>
NNTP-Posting-Host: garnet.berkeley.edu