Re: Ublas library

Hi Joerg, you wrote:

Interesting problem: the naive solution

---------- #include

using namespace boost::numeric::ublas;

template<class Matrix> void ProcessRecursive(Matrix& m) { typedef matrix_range<Matrix> MatrixRange; MatrixRange mr = project(m, range(0,m.size1()/2), range(0,m.size2()/2)); if (mr.size1() > 0 && mr.size2() > 0) ProcessRecursive(mr); }

void StartProcess() { matrix<double> m; ProcessRecursive(m); }

int main() { StartProcess(); }

----------

doesn't terminate to compile ;-)

I'll try to write the code like I want to see: ---------- #include using namespace boost::numeric::ublas; template<class Matrix> void ProcessRecursive(Matrix& m) { typedef matrix_range<typename Matrix::matrix_type> MatrixRange; // this compile only for Matrix == matrix_range, // because for matrix matrix_type is not defined (why not?) MatrixRange mr = project(m, range(0,m.size1()/2), range(0,m.size2()/2)); // here compiler always selects non-specialized version of project, // because m is non-constant reference. if (mr.size1() > 0 && mr.size2() > 0) ProcessRecursive(mr); } void StartProcess() { matrix<double> m(10, 10); // ;) ProcessRecursive(m); } int main() { StartProcess(); } ----------

Which compiler are you using?

VC++ 7.1

...

Do somebody help my to write this code correctly? Or fix library?

How?

1. Add "typedef self_type matrix_type;" in definition of class matrix 2. Add template<class M> BOOST_UBLAS_INLINE matrix_range<M> project (matrix_range<M> &data, const range &r1, const range &r2) { return data.project (r1, r2); } in matix_proxy.hpp (ver. 1.12) on line 3585. It may be need to add the same code for other proxy types . After those changes my code shown above compiles correctly and even runs. ;) Thanks, Alexey.