I am using Numeric Library Bindings for Boost UBlas to solve a simple linear system: __BEGIN__ #include<boost/numeric/ublas/matrix.hpp> #include<boost/numeric/ublas/io.hpp> #include<boost/numeric/bindings/traits/ublas_matrix.hpp> #include<boost/numeric/bindings/lapack/gesv.hpp> #include <boost/numeric/bindings/traits/ublas_vector2.hpp> namespace ublas = boost::numeric::ublas; namespace lapack= boost::numeric::bindings::lapack; int main() { ublas::matrix<float,ublas::column_major> A(3,3); ublas::vector<float> b(3); for(unsigned i=0;i < A.size1();i++) for(unsigned j =0;j < A.size2();j++) { std::cout << "enter element "<<i << j << std::endl; std::cin >> A(i,j); } std::cout << A << std::endl; b(0) = 21; b(1) = 1; b(2) = 17; lapack::gesv(A,b); std::cout << b << std::endl; return 0; } __END__ I tried compiling it with the following command: g++ -I/home/foolb/.boost/include/boost-1_38 -I/home/foolb/.boostnumbind/include/boost-numeric-bindings solve_Axb_byhand.cc -o solve_Axb_byhand but fail with the following error: media/disk/tmp/ccbd973l.o: In function `boost::numeric::bindings::lapack::detail::gesv(int, int, float*, int, int*, float*, int, int*)': solve_Axb_byhand2.cc:(.text._ZN5boost7numeric8bindings6lapack6detail4gesvEiiPfiPiS4_iS5_[boost::numeric::bindings::lapack::detail::gesv(int, int, float*, int, int*, float*, int, int*)]+0x59): undefined reference to `sgesv_' collect2: ld returned 1 exit status __END__ What's wrong with my approach? - G.V