typename Matrix::value_type
norm( const Matrix& A, const std::size_t n )
{
typedef typename Matrix::value_type value_type;
if ( 1 == n )
{
std::vector<value_type> m( A.col() );
for ( std::size_t i = 0; i != A.col(); ++i )
m[i] = std::accumulate( A.col_cbegin(i), A.col_cend(i), value_type(0), []( value_type u, value_type v ) { return u + std::abs(v); } );
return *(std::max_element( m.begin(), m.end() ));
}
if ( 2 == n )
{
return std::sqrt(eigen_power_iteration( A ));
}
assert( !"norm:: other norm algorithm has not been implemented!" );
return value_type(0);
}
typename Matrix::value_type
norm_2( const Matrix& A )
{
return std::sqrt(eigen_power_iteration( A ));
}
T eigen_power_iteration( const matrix<std::complex<T>,D,A_>& A, const T eps = T(1.0e-5) )
{
matrix<std::complex<T>,D,A_> b( A.col(), 1 );
return eigen_power_iteration(A, b.begin(), eps);
}
