Hi, i am not sure about how to improve the speed for your product (maybe defining a specialized axpy_prod), however the times you are speaking about are far too low for any comparison. Try to run the same example but so to have a total time of at least 1sec (better 10secs)

greetings

Riccardo

On Wed, 16 Aug 2006 16:18:05 -0300, Fred wrote
> Hi,
>
> Could you help to decrease time of prod when I use the typedef defined in the code below?
>
>

#include <boost/timer.hpp>
> #include <boost/numeric/ublas/matrix.hpp>
> #include <boost/numeric/ublas/matrix_sparse.hpp>
> #include <boost/numeric/ublas/matrix_proxy.hpp>
> #include <boost/numeric/ublas/vector_sparse.hpp>
> #include <boost/numeric/ublas/vector_proxy.hpp>
> #include <boost/numeric/ublas/vector_of_vector.hpp>
> #include <boost/numeric/ublas/operation.hpp>
> #include <boost/numeric/ublas/io.hpp>
>
> int main () {
>      using namespace boost::numeric::ublas;
>    
>     typedef generalized_vector_of_vector< double, row_major,
>          boost::numeric::ublas::vector< compressed_vector<double> > > matrix;
>     typedef compressed_vector<double> vec_d;
>
> //    typedef matrix<double> matrix;
> //    typedef vector<double> vec_d; 
>    
>     boost::timer  t1;
>     double t_final; 
>        
>     matrix m(3,3);
>      vec_d v(3);
>     vec_d result;
>     for (unsigned i = 0; i < std::min (m.size1 (), v.size ()); ++ i) {
>         for (unsigned j = 0; j < m.size2 (); ++ j)
>              m (i, j) = 3 * i + j;
>          v (i) = i;
>     }
>    
>     std::cout << m << std::endl;
>     std::cout << v << std::endl;
>     
>     int counter = 0;
>     for(int n=0; n<20 ; ++n)
>     {
>         for(int i=0; i<200 ; ++i)
>         {
>           t1.restart();
>           result = prod(m, v); 
>           t_final = t1.elapsed();
>
>           if (t_final > 0.01)
>           {
>              std::cout << "time = " << t_final << std::endl;            
>               counter++;
>           }
>         }
>     }  
>      std::cout << "counter = " << counter << std::endl;
> }
>