diff --git a/org/functions.org b/org/functions.org
index 459328d..0f43872 100644
--- a/org/functions.org
+++ b/org/functions.org
@@ -48,7 +48,7 @@
 :END:
 <<sec:computeReferencePose>>
 
-This Matlab function is accessible [[file:src/computeReferencePose.m][here]].
+This Matlab function is accessible [[file:..//src/computeReferencePose.m][here]].
 
 #+begin_src matlab
   function [WTr] = computeReferencePose(Dy, Ry, Rz, Dh, Dn)
@@ -129,6 +129,7 @@ This Matlab function is accessible [[file:src/computeReferencePose.m][here]].
     WTr = Rty*Rry*Rrz*Rh*Rn;
   end
 #+end_src
+
 * Compute the Sample Position Error w.r.t. the NASS
 :PROPERTIES:
 :header-args:matlab+: :tangle ../src/computeSampleError.m
@@ -136,7 +137,7 @@ This Matlab function is accessible [[file:src/computeReferencePose.m][here]].
 :END:
 <<sec:computeSampleError>>
 
-This Matlab function is accessible [[file:src/computeSampleError.m][here]].
+This Matlab function is accessible [[file:..//src/computeSampleError.m][here]].
 
 #+begin_src matlab
   function [MTr] = computeSampleError(WTm, WTr)
diff --git a/src/computeSampleError.m b/src/computeSampleError.m
new file mode 100644
index 0000000..5c42696
--- /dev/null
+++ b/src/computeSampleError.m
@@ -0,0 +1,20 @@
+function [MTr] = computeSampleError(WTm, WTr)
+% computeSampleError -
+%
+% Syntax: [MTr] = computeSampleError(WTm, WTr)
+%
+% Inputs:
+%    - WTm - Homoegeneous transformation that represent the
+%            wanted pose of the sample with respect to the granite
+%    - WTr - Homoegeneous transformation that represent the
+%            measured pose of the sample with respect to the granite
+%
+% Outputs:
+%    - MTr - Homoegeneous transformation that represent the
+%            wanted pose of the sample expressed in a frame
+%            attached to the top platform of the nano-hexapod
+
+MTr = zeros(4,4);
+
+MTr = [WTm(1:3,1:3)', -WTm(1:3,1:3)'*WTm(1:3,4) ; 0 0 0 1]*WTr;
+end