example_matrix_algebra_eig.cpp

 
#include <Pds/Ra>
    
void eigen_funcs(const Pds::Matrix &A,std::string str);
    
int main(void)
{
    Pds::Matrix A;
    
    A="722.59415501536  14.961544421002  11.686206559208\n"  
      "14.961544421002  0.75443715373377 0.62073051164566\n" 
      "11.686206559208  0.62073051164566 0.58423274700635";
    eigen_funcs(A,"Low convergence");
    
 
    A="2 -2  0\n"  
      "0  3 -3\n" 
      "1  0 -1";
    eigen_funcs(A,"One Lambda with value 0");
    
    return 0;
}
 
void eigen_funcs(const Pds::Matrix &A,std::string str)
{
    Pds::Vector D;
    Pds::Matrix V;
    Pds::Vector E;
    double lambda;
    
    pds_print_info_message("Analizing matrix A");
    pds_print_info_message(str);
    A.Print("A:\n");
 
    std::cout<<std::endl;
    
    D=A.EigenValues();
    D.T().Print("D.T():\n");
    
    std::cout<<std::endl;
    
    V=A.EigenVectors(D);
    V.Print("V:\n");
    
    std::cout<<std::endl;
    
    V=A.EigenVectors(D.GetRows(0,1));
    V.Print("V(0:1):\n");
    
    std::cout<<std::endl;
    
    E=A.EigenDominant(lambda);
    std::cout<<"DOMINANT::\n";
    std::cout<<"lambda:"<<lambda<<"\n";
    E.T().Print("E.T():\t");
 
    std::cout<<std::endl<<std::endl;
    
    Pds::Vector Ev=Pds::Matrix(1,1,1).EigenVector_RegInvIter(2, Pds::Vector(1,1));
    Ev.Print("Ev:\n");
    
};