Re: [Getfem-users] second derivatives of shape function

[Yves Renard]

Dear Wen,

The second derivative of the shape functions on the reference element are provided by a fem object by the method "hess_base_value" (see src/getfem/getfem_fem.h). For polynomial fems, it is computed symbolically (still see src/getfem/getfem_fem.h). At assembly step, these value are computed on each gauss point and stored (fem_precomp structure) such that the computation is done only one for each type of finite element method and each quadrature method. On the real elements, the second derivative of shape function is computed by the method "hess_base_value" of the object "fem_interpolation _context".

Best regards,

Yves



Le 04/02/2016 05:16, Wen Jiang a écrit :

Hi,

I wonder how getfem++ calculates the Hessian (second derivatives of the shape function respect to x, y and z). Where can I find those functions that calculate it? Thanks.

Regards,

Wen

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  Yves Renard (address@hidden)       tel : (33) 04.72.43.87.08
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