I am using MTL(Matrix Template Library) for Matrix computing in Dev-C++ 4.9.8.0 and updated the gcc version from 3.2 to 4.4.1 by installing tdm-mingw-1.908.0-4.4.1-2 and the boost version is 1.37.0. The system is Windows xp The sample code is : #include <boost/numeric/mtl/mtl.hpp> #include "boost/random/normal_distribution.hpp" #include <boost/random.hpp> #include <boost/random/uniform_real.hpp> int main(int argc, char* argv[]) { using namespace mtl; using namespace mtl::matrix; const unsigned n= 5; dense2D<double> A(n, n), B(n, n); morton_dense<double, doppled_64_row_mask> C(n, n), D(n, n); dense2D<double> F(n, n), E(n, n); hessian_setup(A, 3.0); hessian_setup(B, 1.0); hessian_setup(C, 2.0); hessian_setup(D, 11.0); B(1,1)=9.9999; .......................... std::cout << "The matrices are: B=\n" << B <<"\n"; std::cout << "The result is " <<1.0/3.0 <<"\n"; ……………………. But the result is shown that B(1,1) is 10, and 1.0/3.0 is 0.33. How can I get the highest precision of the type double and dense2D<double> for scientific computation? The same question occurred in random number generation in boost random library. Can anyone with kindness help me?