Fix indexes in Transition Matrix HDF5 output

src/libnptm/TransitionMatrix.cpp

@@ -235,8 +235,8 @@ void TransitionMatrix::write_hdf5(string file_name) {
     double *ptr_elements = new double[shape[0] * 2 * shape[1]]();
     for (int ei = 0; ei < shape[0]; ei++) {
       for (int ej = 0; ej < shape[1]; ej++) {
-	ptr_elements[ei * (2 * ej)] = elements[shape[1] * ei + ej].real();
-	ptr_elements[ei * (2 * ej) + 1] = elements[shape[1] * ei  + ej].imag();
+	ptr_elements[shape[1] * ei + 2 * ej] = elements[shape[1] * ei + ej].real();
+	ptr_elements[shape[1] * ei + 2 * ej + 1] = elements[shape[1] * ei  + ej].imag();
       }
     }
     rec_ptr_list.append(ptr_elements);