|
|
Ublas : |
From: Karl Meerbergen (karl.meerbergen_at_[hidden])
Date: 2008-08-22 02:14:22
Hi,
I guess your matrix is
1 2 3
4 5 6
7 8 9
This is a singular matrix. You can do a factorization but not a solve
afterwards.
Best regards,
Karl
Иволгин Ðрдалион wrote:
> Hello, everybody!
>
> I found a page about LU-decomposition on Effective uBLAS wiki. Everything looked neat, and I decided to write simple example like this below:
>
> #include <boost/numeric/ublas/io.hpp>
> #include <boost/numeric/ublas/lu.hpp>
>
> using namespace boost::numeric::ublas;
>
> int main () {
> matrix<int> A(3,3), B(identity_matrix<int>(3));
> for (int i=0; i<3; ++i)
> for (int j=0; j<3; ++j)
> A(i,j)=3*i+j+1;
>
> std::cout << A << std::endl;
> std::cout << B << std::endl;
>
> permutation_matrix<> pm(3);
>
> lu_factorize<matrix<int>, permutation_matrix<> >(A, pm);
> lu_substitute(A, pm, B);
>
> std::cout << A << std::endl;
> std::cout << B << std::endl;
>
> return EXIT_SUCCESS;
> }
>
> But when I try to run the compiled executable, I got a run-time assertion with this text:
>
> Check failed in .../include/boost/numeric/ublas/lu.hpp at line 157:
> singular != 0 || detail::expression_type_check (prod (triangular_adaptor<matrix_type, unit_lower> (m), triangular_adaptor<matrix_type, upper> (m)), cm)
>
> Maybe someone had already faced this problem?
>
> P.S. On the page about LU-decomposition there was something about getting recent version of lu.hpp from Boost CVS. But the link in Boost::uBLAS documentation seems to be broken.
>
> P.P.S. I have: MS Windows Vista 32-bit with MinGW g++ 3.4.5 compiler. (Boost version is 1.36.0).
> _______________________________________________
> ublas mailing list
> ublas_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/ublas
>