Hi Jozef,

On 07/15/2015 10:14 PM, Robert Cimrman wrote:

On 07/15/2015 07:07 PM, Jozef Vesely wrote:

To evaluate the the variable at given point you first evaluate basis functions at given point and then take their linear combination depending on the values on vertices (quarature points) of given element. Isn't it possible to evaluate gradients of basis functions at given point weight them by vertex values of original field and get the result?

No, but I will add that functionality to Variable.evaluate_at() tomorrow - it should be pretty easy. I will let you know when it's ready.

you can try [1] (use u.evaluate_at(p, mode='grad') or probe call with the same argument). Let me know if that works for you and I will then merge it into master. It passes the updated test test_invariance_qp() in in tests/test_mesh_interp.py.

r.