CFD Online Discussion Forums - Gradient of velocity

Hi, guys.
I'm trying to get value of gradient of velocity.
But I can't get gradient values at the face.

I mean, first and last nodes value are strange.

I attached graph of 1st, 2nd order gradient of velocity.

How can I get right values?

It's my code.

Code:

DEFINE_ADJUST(my_adjust, d)

{

 Thread *t,;

 cell_t c, ;

 face_t f;

 

 if(N_ITER > 1)

 {

  thread_loop_c(t, d)

  {

   begin_c_loop (c, t)

   {

    C_UDSI(c,t,0) = C_U(c,t);

   }

   end_c_loop (c, t)

  }

  thread_loop_c(t, d)

  {

   begin_c_loop (c, t)

   {

    C_UDSI(c,t,1) = C_UDSI_G(c,t,0)[1];

   }

   end_c_loop (c, t)

  }

  thread_loop_c(t, d)

  {

   begin_c_loop (c, t)

   {

    C_UDSI(c,t,2) = C_UDSI_G(c,t,1)[1];

   }

   end_c_loop (c, t)

  }

 }

}

Thanks. ^^