ublas

I understand that doing something like the following: auto&& x = Matrix1() + Matrix2() + Matrix3(); std::cout << x(2,3) << std::endl; Will cause a silent runtime error if the matrix operations use expression templates (such as boost::ublas ). Is there any way of designing expression templates to prevent the compiler from compiling such code that may result in the use of expired temporaries at runtime? (I've attempted unsuccessfully to work around this issue, the attempt is here ) Is there any way of designing expression templates to prevent the compiler from compiling such code that may result

I am trying to implement certain matrix operations but I am lost in the internals of ublas library. is there a resource such as tutorial or an example on how to implement new ublas matrix expressions? Thanks Don't know if it'll help, but there's a wiki page on extending uBlas here . That expression template stuff really blows my mind. :) My suggestion is to just template your new functions so you don't have to worry about matrix expressions or ublas internals. For example, if you wanted to write your own inverse function, write it as a template: template<typename MATRIX_IN, typename MATRIX_OUT

Is there a way to improve the boost ublas product performance? I have two matrices A,B which i want to mulitply/add/sub/... In MATLAB vs. C++ i get the following times [s] for a 2000x2000 matrix Operations OPERATION | MATLAB | C++ (MSVC10) A + B | 0.04 | 0.04 A - B | 0.04 | 0.04 AB | 1.0 | 62.66 A'B' | 1.0 | 54.35 Why there is such a huge performance loss here? The matrices are only real doubles. But i also need positive definites,symmetric,rectangular products. EDIT: The code is trivial matrix<double> A( 2000 , 2000 ); // Fill Matrix A matrix<double> B = A; C = A + B; D = A - B; E = prod(A,B)

I have implemented one matrix multiplication with boost::numeric::ublas::matrix (see my full, working boost code ) Result result = read (); boost::numeric::ublas::matrix<int> C; C = boost::numeric::ublas::prod(result.A, result.B); and another one with the standard algorithm (see full standard code ): vector< vector<int> > ijkalgorithm(vector< vector<int> > A, vector< vector<int> > B) { int n = A.size(); // initialise C with 0s vector<int> tmp(n, 0); vector< vector<int> > C(n, tmp); for (int i = 0; i < n; i++) { for (int k = 0; k < n; k++) { for (int j = 0; j < n; j++) { C[i][j] += A[i][k] * B

I am writing a Matlab extension using the C++ ublas library, and I would like to be able to initialize my ublas vectors from the C arrays passed by the Matlab interpeter. How can I initialize the ublas vector from a C array without (for the sake of efficiency) explicitly copying the data. I am looking for something along the following lines of code: using namespace boost::numeric::ublas; int pv[10] = { 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 }; vector<int> v (pv); In general, is it possible to initialize a C++ std::vector from an array? Something like this: #include <iostream> #include <vector> using