void _step2(V_type & W) { assert(step==1); //if (step==1) return; step=2; _compute_det(W); info = lapack::getri(W, ipiv); if (info!=0) throw matrix_inverse_exception() << "Inverse/Det error : matrix is not invertible"; }
VT det() { V_type W = fortran_view(V); _step1(W); _compute_det(W); return _det;}
value_type det() { V_type W = fortran_view(a); _step1(W); _compute_det(W); return _det; }