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Re: Sparse Matrix, Memory Allocation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg31643] Re: Sparse Matrix, Memory Allocation
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Fri, 23 Nov 2001 05:46:08 -0500 (EST)
  • Organization: Universitaet Leipzig
  • References: <9t2tnm$6pi$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

since

Developer`SparseLinearSolve[K,x]

use a sparse representation of the matrix of the
form {{i1,j1}->a1,{i2,j2}->a2,..}

it would be useless to feed the dense representation
into SparseLinearSolve[].

If you don't get more information like the band
width of the matrix no one can reporduce the problem.

Regards
  Jens 

Inkyu Rhee wrote:
> 
> I have a 70000 by 70000(or more) banded sparse matrix.
> and this matrix will be updated by specific law for 50 loops.
> In each loop, I need to linear solution of this.
> 
> My prblems are:
> 
> I could not specify this matrix:
> 
> K=Table[0,{70000},{70000}];(* Initialize the matrix K *)
> 
> when I trying this in my machines ((1) sun:ram 750M, swap 2665M,
> (2) window:A800mhz, 128Mb),
> machine gives me 'Out of Memory, Exiting'.
> How do you specify this matrix efficiently?
> 
> If this works well, I will update these components of matrix
> using certain law. Then I need to solve the equations.
> 
> Developer`SparseLinearSolve[K,x]


> 
> I tried this part using 10000 by 10000 instead of 70000.
> It also give me 'Out of Memory ...'.
> 
> Thanks for any help,
> 
> I. Rhee


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