# [Getdp] grad on the surface

**Andre Antunes**
andre.antunes at tuebingen.mpg.de

*Sat Jan 19 03:15:29 CET 2013*

Dear all
I'll try to go concise.
I would like to know how exactly the Grad is computed in the PostProcessing stage.
Looking at the solution msh file for the Grad, I can see that the $ElementNodeData for each element has the exact same value for all nodes.
What is happening? Do these values correspond to some average that is begin done and thus represent the Grad at the centre of the element? How was it calculated? Is there a different way to compute the gradient (e.g. node-wise)?
Best regards,
Andre