[Boost-users] Boost uBLAS Sparse Matrices Question

Subject: [Boost-users] Boost uBLAS Sparse Matrices Question
From: Eamonn Hynes (hynese_at_[hidden])
Date: 2010-01-20 11:08:02

Greetings users,

Anyone know how to convert a matrix<int> to a compressed_vector<int> using
the boost/numeric/ublas/ library?

Here is a code snippet:

#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/io.hpp>
using namespace boost::numeric::ublas;
using namespace std;
#include <fstream>

int A=2000;
int D=2000;

int main()
{
        matrix<int> ADf(A,D);   //Author-Document (full)

        fstream IN;
        IN.open("./eoh_ADf");
        for(unsigned i=0;i<ADf.size1();++i)
        {
                for (unsigned j=0;j<ADf.size2();++j)
                {
                        IN>>ADf(i,j);
                }
        }
        IN.close();

        cout<<ADf<<endl;
        return 0;
}

I badly need to convert the matrix ADf into sparse form... Isn't there
some function to convert ADf into ADs (AD sparse)? i.e. ADs=sparse(ADf)...

Let's say ADf isn't a 2000x2000, but simply a 5x5:

ADf=[[1,-1,0,-3,0],[-1,5,0,0,0],[0,0,4,6,4],[-3,0,6,7,0],[0,0,4,0,-5]]

I want this converted to:

values = [1 -1 -3 -2 5 4 6 4 -4 2 7 8 -5]
columns = [1 2 4 1 2 3 4 5 1 3 4 2 5]
rowIndex = [1 4 6 9 12 14]

Any help that users can offer me would be much appreciated.

Thanks in advance,

Eamorr