[Getfem-users] second derivative of linear elements

[Wen Jiang]

Dear all,

I tried to calculate the second derivative in getfem using compute hessian. For linear elements, the second derivative of the shape function should be zero but it seems that the results of hessian computed in getfem is not zero. Could you tell me how is the hessian computed in getfem for linear elements? Thanks.

Regards,
Wen