Usually something similar to:
typedef boost::numeric::ublas::matrix<double> matrix_type; const matrix_type get_matrix(void) { matrix_type result(1, 3); result(0, 0) = 1; result(0, 1) = 2; result(0, 2) = 3; return result; } const matrix_type arrayM = get_matrix();
You can also try something like this (mostly unverified):
#include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/io.hpp> template <typename T, typename L = boost::numeric::ublas::row_major, typename A = boost::numeric::ublas::unbounded_array<T> > class matrix_builder { public: // types typedef boost::numeric::ublas::matrix<T, L, A> matrix_type; typedef typename matrix_type::size_type size_type; // creation matrix_builder(size_type pRows, size_type pColumns) : mMatrix(pRows, pColumns), mRow(0), mColumn(0) {} matrix_builder& operator()(const T& pValue) { mMatrix(mRow, mColumn) = pValue; if (++mColumn == mMatrix.size2()) { mColumn = 0; mRow++; } return *this; } // access operator const matrix_type&(void) const { return mMatrix; } private: // non copyable matrix_builder(const matrix_builder&); matrix_builder& operator=(const matrix_builder&); // members matrix_type mMatrix; size_type mRow; size_type mColumn; }; typedef boost::numeric::ublas::matrix<double> matrix_type; static const matrix_type m1 = matrix_builder<double>(3, 1) (1)(2)(3); static const matrix_type m2 = matrix_builder<double>(3, 3) (1)(2)(3) (4)(5)(6) (7)(8)(9); int main(void) { std::cout << m1 << std::endl; std::cout << m2 << std::endl; }
The same idea, more general. Also a little more visual, which can be enjoyable.