diff --git a/test/test.hpp b/test/test.hpp
index 4af4e024..d707ff8f 100644
--- a/test/test.hpp
+++ b/test/test.hpp
@@ -80,17 +80,40 @@ std::array<std::size_t, 4> lindex_to_pos_arr( std::size_t const d1
   return p;
 }
 
-std::array<std::size_t, 4> std_res_to_pos4D ( int* res
-                                            , int* begin
-                                            , std::size_t const d1
-                                            , std::size_t const d2
-                                            , std::size_t const d3
-                                            )
+std::array<std::size_t, 2> lindex_to_pos_arr( std::size_t const d1
+                                    , int const lindex
+                                    )
 {
-  auto dist = static_cast<std::size_t>(std::distance(begin, res));
+  int remains = lindex;
+  std::array<std::size_t, 2> p;
+  std::fill(p.begin(), p.end(), 0);
+  p[0] = remains / d1;
+  remains -= p[0] * d1;
+  p[1] = remains;
+  return p;
+}
+
+std::array<std::size_t, 4> std_res_to_pos ( int* res
+                                          , int* begin
+                                          , std::size_t const d1
+                                          , std::size_t const d2
+                                          , std::size_t const d3
+                                          )
+{
+  std::size_t dist = static_cast<std::size_t>(std::distance(begin, res));
   return lindex_to_pos_arr(d1, d2, d3, dist);
 }
 
+std::array<std::size_t, 2> std_res_to_pos ( int* res
+                                          , int* begin
+                                          , std::size_t const d1
+                                          )
+{
+  std::size_t dist = static_cast<std::size_t>(std::distance(begin, res));
+  return lindex_to_pos_arr(d1, dist);
+}
+
+
 
 template<typename T, typename S>
 void fill_data(T* data, S shp, bool fill)