diff --git a/ocaml/Block.ml b/ocaml/Block.ml
index 6790df7..6941b21 100644
--- a/ocaml/Block.ml
+++ b/ocaml/Block.ml
@@ -195,16 +195,6 @@ let update_raw_data ?(locked=true) () =
        ) result
   in
 
-  let rec transform new_list = function
-   | [] -> new_list
-   | head :: tail ->
-     let head = String.trim head in
-     let item = of_string head in
-     match item with
-       | None   -> transform new_list tail
-       | Some x -> transform (x::new_list) tail
-  in
-
   if Qmcchem_config.binary_io then
     begin
       let result =
@@ -237,6 +227,16 @@ let update_raw_data ?(locked=true) () =
     end
   else
     begin
+      let rec transform new_list = function
+      | [] -> new_list
+      | head :: tail ->
+        let head = String.trim head in
+        let item = of_string head in
+        match item with
+          | None   -> transform new_list tail
+          | Some x -> transform (x::new_list) tail
+      in
+
       let result =
         let rec aux ic accu =
           let l =
diff --git a/ocaml/Qmcchem_result.ml b/ocaml/Qmcchem_result.ml
index 102bae7..68106d8 100644
--- a/ocaml/Qmcchem_result.ml
+++ b/ocaml/Qmcchem_result.ml
@@ -139,9 +139,8 @@ let display_summary ~range =
   and print_property property = 
     let p = Random_variable.of_raw_data ~range property
     in
-    Printf.printf "%20s : %s\n"
-     (Property.to_string property)
-     (Random_variable.to_string p)
+    Printf.printf "%20s : %!" (Property.to_string property);
+    Printf.printf "%s\n%!" (Random_variable.to_string p)
   in
   List.iter print_property properties ;
 
diff --git a/ocaml/Random_variable.ml b/ocaml/Random_variable.ml
index 13482ab..f408564 100644
--- a/ocaml/Random_variable.ml
+++ b/ocaml/Random_variable.ml
@@ -209,7 +209,7 @@ let ave_error { property ; data } =
         else
           ( Average.of_float (sum /. ansum), None)
       end
-    | (x,w) :: tail ->
+    | (x, w) :: tail ->
       begin
         let avcu0 = avsum /. ansum in
         let xw = x *. w in
@@ -633,6 +633,7 @@ let to_string p =
               in
               Printf.sprintf "%16.10f" ave
       else
+begin
           match ave_error p with
           | (ave, Some error) ->
               let idxmax =
@@ -645,16 +646,18 @@ let to_string p =
                       Error.to_float ~idx error
                     in
                     let s =
-                      Printf.sprintf "%8d :  %16.10f +/- %16.10f ;\n" (idx+1) ave error
+                      Printf.sprintf "%8d :  %16.10f +/- %16.10f ;" (idx+1) ave error
                     in
-                    f (accu ^ s) (idx+1)
+                    (f [@tailcall]) (s :: accu) (idx+1)
                 else
-                    accu
+                    List.rev (" ]" :: accu)
               in
-              (f "[ \n" 0) ^ " ]"
+              f ["[ \n"] 0
+              |> String.concat "\n"
           | (ave, None) ->
               Average.to_float ave
-              |> Printf.sprintf "%16.10f"
+              |> Printf.sprintf "%16.10f%!"
+end
     end
 
 
diff --git a/ocaml/Sample.ml b/ocaml/Sample.ml
index f1f6c51..4a2d64f 100644
--- a/ocaml/Sample.ml
+++ b/ocaml/Sample.ml
@@ -58,7 +58,10 @@ let of_bytes b =
   | 8 -> let x = Qptypes.float_of_bytes b in
          One_dimensional x
   | l -> let len = l/8 in
+let result = 
          Multidimensional ( Array.init len (fun i ->
                                Bytes.get_int64_le b (i*8)
                                |> Int64.float_of_bits ),
                            len )
+in
+result