PETSCSPACEPTRIMMED#

“ptrimmed” - A PetscSpace object that encapsulates a trimmed polynomial space. Trimmed polynomial spaces are defined for kk-forms, and are defined by PrΛk(Rn)=mathcalPr1Λk(Rn)κ[Hr1Λk+1(Rn)], \mathcal{P}^-_r \Lambda^k(\mathbb{R}^n) = mathcal{P}_{r-1} \Lambda^k(\mathbb{R}^n) \oplus \kappa [\mathcal{H}_{r-1} \Lambda^{k+1}(\mathbb{R}^n)], where Hr1\mathcal{H}_{r-1} are homogeneous polynomials and κ\kappa is the Koszul differential. This decomposition is detailed in ``Finite element exterior calculus’’, Arnold, 2018.

Notes#

Trimmed polynomial spaces correspond to several common conformal approximation spaces in the de Rham complex#

In H1H^1 (k=0\sim k=0), trimmed polynomial spaces are identical to the standard polynomial spaces, PrPr\mathcal{P}_r^- \sim P_r.

In H(curl)H(\text{curl}), (k=1\sim k=1), trimmed polynomial spaces are equivalent to H(curl)H(\text{curl})-Nedelec spaces of the first kind and can be written as {[Pr1(R2)]2rot(x)Hr1(R2),n=2,[Pr1(R3)]3x×[Hr1(R3)]3,n=3. \begin{cases} [P_{r-1}(\mathbb{R}^2)]^2 \oplus \mathrm{rot}(\bf{x}) H_{r-1}(\mathbb{R}^2), & n = 2, \\ [P_{r-1}(\mathbb{R}^3)]^3 \oplus \bf{x} \times [H_{r-1}(\mathbb{R}^3)]^3, & n = 3. \end{cases}

In H(div)H(\text{div}) (k=n1\sim k=n-1), trimmed polynomial spaces are equivalent to Raviart-Thomas spaces (n=2n=2) and H(div)H(\text{div})-Nedelec spaces of the first kind (n=3n=3), and can be written as [Pr1(Rn)]nxHr1(Rn). [P_{r-1}(\mathbb{R}^n)]^n \oplus \bf{x} H_{r-1}(\mathbb{R}^n).

In L2L_2, (k=n\sim k=n), trimmed polynomial spaces are identical to the standard polynomial spaces of one degree less, PrPr1\mathcal{P}_r^- \sim P_{r-1}.

See Also#

PetscSpace, PetscSpaceType, PetscSpaceCreate(), PetscSpaceSetType(), PetscDTPTrimmedEvalJet()

Level#

intermediate

Location#

src/dm/dt/space/impls/ptrimmed/spaceptrimmed.c


Index of all SPACE routines
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Index of all manual pages