diff --git a/TODO.org b/TODO.org
index 250dd79..1fad144 100644
--- a/TODO.org
+++ b/TODO.org
@@ -14,4 +14,5 @@ context.
 * Performance info
 * Benchmark interpolation of basis functions
 * Complex numbers
+* Adjustable number for derivatives (1,2,3)
 
diff --git a/src/qmckl_distance.org b/src/qmckl_distance.org
index 5bdbb53..6795b98 100644
--- a/src/qmckl_distance.org
+++ b/src/qmckl_distance.org
@@ -43,12 +43,14 @@ MunitResult test_qmckl_distance() {
    Computes the matrix of the squared distances between all pairs of
    points in two sets, one point within each set:
    \[
-   C_{ij} = \sum_{k=1}^3 (A_{i,k}-B_{j,k})^2
+   C_{ij} = \sum_{k=1}^3 (A_{k,i}-B_{k,j})^2
    \]
 
 *** Arguments
 
     | =context=  | input  | Global state                                 |
+    | =transa=   | input  | Array =A= is =N=: Normal, =T=: Transposed   |
+    | =transb=   | input  | Array =B= is =N=: Normal, =T=: Transposed   |
     | =m=        | input  | Number of points in the first set            |
     | =n=        | input  | Number of points in the second set           |
     | =A(lda,3)= | input  | Array containing the $m \times 3$ matrix $A$ |
@@ -63,16 +65,24 @@ MunitResult test_qmckl_distance() {
     - =context= is not 0
     - =m= > 0
     - =n= > 0
-    - =lda= >= m
-    - =ldb= >= n
-    - =ldc= >= m
+    - =lda= >= 3 if =transa= is =N=
+    - =lda= >= m if =transa= is =T=
+    - =ldb= >= 3 if =transb= is =N=
+    - =ldb= >= n if =transb= is =T=
+    - =ldc= >= m if =transa= is =
     - =A= is allocated with at least $3 \times m \times 8$ bytes
     - =B= is allocated with at least $3 \times n \times 8$ bytes
     - =C= is allocated with at least $m \times n \times 8$ bytes
 
+*** Performance 
+
+    This function might be more efficient when =A= and =B= are
+    transposed.
+
 *** Header
     #+BEGIN_SRC C :comments link :tangle qmckl_distance.h
 qmckl_exit_code qmckl_distance_sq(qmckl_context context,
+				  char transa, char transb,
 				  int64_t m, int64_t n,
 				  double *A, int64_t lda,
 				  double *B, int64_t ldb,
@@ -81,19 +91,21 @@ qmckl_exit_code qmckl_distance_sq(qmckl_context context,
 
 *** Source
     #+BEGIN_SRC f90 :comments link  :tangle qmckl_distance.f90
-integer function qmckl_distance_sq_f(context, m, n, A, LDA, B, LDB, C, LDC) result(info)
+integer function qmckl_distance_sq_f(context, transa, transb, m, n, A, LDA, B, LDB, C, LDC) result(info)
   implicit none
   integer*8  , intent(in)  :: context
+  character  , intent(in)  :: transa, transb
   integer*8  , intent(in)  :: m, n
   integer*8  , intent(in)  :: lda
-  real*8     , intent(in)  :: A(lda,3)
+  real*8     , intent(in)  :: A(lda,*)
   integer*8  , intent(in)  :: ldb
-  real*8     , intent(in)  :: B(ldb,3)
+  real*8     , intent(in)  :: B(ldb,*)
   integer*8  , intent(in)  :: ldc
-  real*8     , intent(out) :: C(ldc,n)
+  real*8     , intent(out) :: C(ldc,*)
 
   integer*8 :: i,j
   real*8    :: x, y, z
+  integer   :: transab
 
   info = 0
 
@@ -112,40 +124,107 @@ integer function qmckl_distance_sq_f(context, m, n, A, LDA, B, LDB, C, LDC) resu
      return
   endif
 
-  if (LDA < m) then
-     info = -4
-     return
+  if (transa == 'N' .or. transa == 'n') then
+     transab = 0
+  else if (transa == 'T' .or. transa == 't') then
+     transab = 1
+  else
+     transab = -100
   endif
 
-  if (LDB < n) then
+  if (transb == 'N' .or. transb == 'n') then
+     continue
+  else if (transa == 'T' .or. transa == 't') then
+     transab = transab + 2
+  else
+     transab = -100
+  endif
+
+  if (transab < 0) then
+     info = -4
+     return 
+  endif
+
+  if (iand(transab,1) == 0 .and. LDA < 3) then
      info = -5
      return
   endif
 
-  if (LDC < m) then
+  if (iand(transab,1) == 1 .and. LDA < m) then
      info = -6
      return
   endif
 
-  do j=1,n
-     do i=1,m
-	x = A(i,1) - B(j,1)
-	y = A(i,2) - B(j,2)
-	z = A(i,3) - B(j,3)
-	C(i,j) = x*x + y*y + z*z
-     end do
-  end do
+  if (iand(transab,2) == 0 .and. LDA < 3) then
+     info = -6
+     return
+  endif
 
+  if (iand(transab,2) == 2 .and. LDA < m) then
+     info = -7
+     return
+  endif
+
+
+  select case (transab)
+     
+  case(0)
+
+     do j=1,n
+        do i=1,m
+           x = A(1,i) - B(1,j)
+           y = A(2,i) - B(2,j)
+           z = A(3,i) - B(3,j)
+           C(i,j) = x*x + y*y + z*z
+        end do
+     end do
+
+  case(1)
+
+     do j=1,n
+        do i=1,m
+           x = A(i,1) - B(1,j)
+           y = A(i,2) - B(2,j)
+           z = A(i,3) - B(3,j)
+           C(i,j) = x*x + y*y + z*z
+        end do
+     end do
+
+  case(2)
+
+     do j=1,n
+        do i=1,m
+           x = A(1,i) - B(j,1)
+           y = A(2,i) - B(j,2)
+           z = A(3,i) - B(j,3)
+           C(i,j) = x*x + y*y + z*z
+        end do
+     end do
+
+  case(3)
+
+     do j=1,n
+        do i=1,m
+           x = A(i,1) - B(j,1)
+           y = A(i,2) - B(j,2)
+           z = A(i,3) - B(j,3)
+           C(i,j) = x*x + y*y + z*z
+        end do
+     end do
+
+  end select
+  
 end function qmckl_distance_sq_f
     #+END_SRC
 
 *** C interface                                                   :noexport:
     #+BEGIN_SRC f90 :comments link  :tangle qmckl_distance.f90
-integer(c_int32_t) function qmckl_distance_sq(context, m, n, A, LDA, B, LDB, C, LDC) &
+integer(c_int32_t) function qmckl_distance_sq(context, transa, transb, m, n, A, LDA, B, LDB, C, LDC) &
      bind(C) result(info)
   use, intrinsic :: iso_c_binding
   implicit none
   integer (c_int64_t) , intent(in) , value :: context
+  character (c_char)  , intent(in) , value :: transa, transb
   integer (c_int64_t) , intent(in) , value :: m, n
   integer (c_int64_t) , intent(in) , value :: lda
   real    (c_double)  , intent(in)         :: A(lda,3)
@@ -155,17 +234,18 @@ integer(c_int32_t) function qmckl_distance_sq(context, m, n, A, LDA, B, LDB, C,
   real    (c_double)  , intent(out)        :: C(ldc,n)
 
   integer, external :: qmckl_distance_sq_f
-  info = qmckl_distance_sq_f(context, m, n, A, LDA, B, LDB, C, LDC)
+  info = qmckl_distance_sq_f(context, transa, transb, m, n, A, LDA, B, LDB, C, LDC)
 end function qmckl_distance_sq
     #+END_SRC
 
     #+BEGIN_SRC f90 :comments link  :tangle qmckl_distance.fh
   interface
-     integer(c_int32_t) function qmckl_distance_sq(context, m, n, A, LDA, B, LDB, C, LDC) &
+     integer(c_int32_t) function qmckl_distance_sq(context, transa, transb, m, n, A, LDA, B, LDB, C, LDC) &
           bind(C) 
        use, intrinsic :: iso_c_binding
        implicit none
        integer (c_int64_t) , intent(in) , value :: context
+       character (c_char)  , intent(in) , value :: transa, transb
        integer (c_int64_t) , intent(in) , value :: m, n
        integer (c_int64_t) , intent(in) , value :: lda
        integer (c_int64_t) , intent(in) , value :: ldb
@@ -192,22 +272,30 @@ integer(c_int32_t) function test_qmckl_distance_sq(context) bind(C)
 
   m = 5
   n = 6
-  LDA = 6
-  LDB = 10
+  LDA = m
+  LDB = n
   LDC = 5
 
-  allocate( A(LDA,3), B(LDB,3), C(LDC,n) )
+  allocate( A(LDA,m), B(LDB,n), C(LDC,n) )
 
-  do j=1,3
+  do j=1,m
      do i=1,m
 	A(i,j) = -10.d0 + dble(i+j)
      end do
+  end do
+  do j=1,n
      do i=1,n
 	B(i,j) = -1.d0 + dble(i*j)
      end do
   end do
 
-  test_qmckl_distance_sq = qmckl_distance_sq(context, m, n, A, LDA, B, LDB, C, LDC)
+  test_qmckl_distance_sq = qmckl_distance_sq(context, 'X', 't', m, n, A, LDA, B, LDB, C, LDC)
+  if (test_qmckl_distance_sq == 0) return 
+
+  test_qmckl_distance_sq = qmckl_distance_sq(context, 't', 'X', m, n, A, LDA, B, LDB, C, LDC)
+  if (test_qmckl_distance_sq == 0) return 
+
+  test_qmckl_distance_sq = qmckl_distance_sq(context, 'T', 't', m, n, A, LDA, B, LDB, C, LDC)
   if (test_qmckl_distance_sq /= 0) return 
 
   test_qmckl_distance_sq = -1
@@ -220,6 +308,49 @@ integer(c_int32_t) function test_qmckl_distance_sq(context) bind(C)
 	if ( dabs(1.d0 - C(i,j)/x) > 1.d-14 ) return
      end do
   end do
+  
+  test_qmckl_distance_sq = qmckl_distance_sq(context, 'n', 'T', m, n, A, LDA, B, LDB, C, LDC)
+  if (test_qmckl_distance_sq /= 0) return 
+
+  test_qmckl_distance_sq = -1
+
+  do j=1,n
+     do i=1,m
+	x =  (A(1,i)-B(j,1))**2 + &
+	     (A(2,i)-B(j,2))**2 + &
+	     (A(3,i)-B(j,3))**2
+	if ( dabs(1.d0 - C(i,j)/x) > 1.d-14 ) return
+     end do
+  end do
+
+  test_qmckl_distance_sq = qmckl_distance_sq(context, 'T', 'n', m, n, A, LDA, B, LDB, C, LDC)
+  if (test_qmckl_distance_sq /= 0) return 
+
+  test_qmckl_distance_sq = -1
+
+  do j=1,n
+     do i=1,m
+	x =  (A(i,1)-B(1,j))**2 + &
+	     (A(i,2)-B(2,j))**2 + &
+	     (A(i,3)-B(3,j))**2
+	if ( dabs(1.d0 - C(i,j)/x) > 1.d-14 ) return
+     end do
+  end do
+
+  test_qmckl_distance_sq = qmckl_distance_sq(context, 'n', 'N', m, n, A, LDA, B, LDB, C, LDC)
+  if (test_qmckl_distance_sq /= 0) return 
+
+  test_qmckl_distance_sq = -1
+
+  do j=1,n
+     do i=1,m
+	x =  (A(1,i)-B(1,j))**2 + &
+	     (A(2,i)-B(2,j))**2 + &
+	     (A(3,i)-B(3,j))**2
+	if ( dabs(1.d0 - C(i,j)/x) > 1.d-14 ) return
+     end do
+  end do
+
   test_qmckl_distance_sq = 0
 
   deallocate(A,B,C)
@@ -230,14 +361,14 @@ end function test_qmckl_distance_sq
 int test_qmckl_distance_sq(qmckl_context context);
 munit_assert_int(0, ==, test_qmckl_distance_sq(context));
     #+END_SRC
-* End of files
+* End of files                                                     :noexport:
 
-*** Header                                                         :noexport:
+*** Header
   #+BEGIN_SRC C :comments link :tangle qmckl_distance.h
 #endif
   #+END_SRC
 
-*** Test                                                           :noexport:
+*** Test
   #+BEGIN_SRC C :comments link :tangle test_qmckl_distance.c
   if (qmckl_context_destroy(context) != QMCKL_SUCCESS)
     return QMCKL_FAILURE;