用sparselib库解稀疏矩阵线性方程组

王朝other·作者佚名  2006-01-09
窄屏简体版  字體: |||超大  

下面用GMRES(Generalized Minimum Residual Method)

演示用sparselib解线性方程组。

在matlab里可以用以下的命令,

GMRES(A,B,RESTART,TOL,MAXIT);

类似得在vc++中可以这样:

#include <cstdlib>

#include <iostream>

#include "compcol_double.h"

#include "mvvtp.h"

#include "mvblasd.h"

#include "ilupre_double.h"

#include "gmres.h"

#include "spblas.h"

#include "mvm.h"

//#include MATRIX_H

//using namespace std;

int main(void)

{

double val[] = {10, 3, 3, 9, 7, 8, 4, 9, 8, 7, 7, 9, -2, 5, 9, 2, 3, 13, -1};

int row_ind[] = {0, 1, 3, 1, 2, 4, 5, 2, 3, 2, 3, 4, 0, 3, 4, 5, 1, 4, 5};

int col_ptr[] = {0, 3, 7, 9, 12, 16, 19};

int maxit = 150; // maximum iteration

int nUnknown = 6; // unknown, the size of Jacobi

int nNonZero = 19; // nonZero values in the matrix

int results;

int restart = 10; // restart iterations

double tol = 1.e-6; // convergence tolerance

CompCol_Mat_double Jacobi(nUnknown, nUnknown, nNonZero, val, row_ind, col_ptr);

//cout << Jacobi;

CompCol_ILUPreconditioner_double M(Jacobi); // construct preconditioner

MATRIX_double H(restart+1, restart, 0.0); // storage for upper Hessenberg H;

VECTOR_double xi(nUnknown, 0);

VECTOR_double rhs(nUnknown);

for(int i=0; i<nUnknown; i++) rhs(i) =i+1;

/**********************************************************************

* maxit AND tol WILL BE CHANGED AFTER ONE CALL OF GMRES, **

* SO FOR NEXT CALL, YOU SHOULD RESTORE THE OLD VALUE OF THEM **

***********************************************************************/

results = GMRES(Jacobi, xi, rhs, M, H, restart, maxit, tol); // call solver

cout << "GMRES flag = " << results << endl;

cout << "Iterations performed: " << maxit << endl;

cout << "Tolerance achieved :" << tol << endl;

for (i = 0; i < nUnknown; i ++){

cout <<"xi["<<i<<"]="<<xi[i]<<"\n";

}

return results;

}

运行结果:

xi[0]= 0.248096

xi[1]= 0.705373

xi[2]=-1.49092

xi[3]= 1.64009

xi[4]= 0.740481

xi[5]=-1.69755

注意这里的稀疏矩阵用Harwell-Boeing格式存储,

10 0 0 0 -2 0

3 9 0 0 0 3

0 7 9 7 0 0

3 0 8 7 5 0

0 8 0 9 9 13

0 4 0 0 2 -1

具体可以参考

I.S. Duff,R.G.Grimes,and J.G.Lewis,Sparse matrix test problems,ACM Trans.Math.Soft

 
 
 
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