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Degree 2 Lagrange on a interval
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- \(R\) is the reference interval. The following numbering of the subentities of the reference is used:
- \(\mathcal{V}\) is spanned by: \(1\), \(x\), \(x^{2}\)
- \(\mathcal{L}=\{l_0,...,l_{2}\}\)
- Functionals and basis functions:
\(\displaystyle l_{0}:v\mapsto v(0)\)
\(\displaystyle \phi_{0} = 2 x^{2} - 3 x + 1\)
This DOF is associated with vertex 0 of the reference element.
\(\displaystyle \phi_{0} = 2 x^{2} - 3 x + 1\)
This DOF is associated with vertex 0 of the reference element.
\(\displaystyle l_{1}:v\mapsto v(1)\)
\(\displaystyle \phi_{1} = x \left(2 x - 1\right)\)
This DOF is associated with vertex 1 of the reference element.
\(\displaystyle \phi_{1} = x \left(2 x - 1\right)\)
This DOF is associated with vertex 1 of the reference element.
\(\displaystyle l_{2}:v\mapsto v(\tfrac{1}{2})\)
\(\displaystyle \phi_{2} = 4 x \left(1 - x\right)\)
This DOF is associated with edge 0 of the reference element.
\(\displaystyle \phi_{2} = 4 x \left(1 - x\right)\)
This DOF is associated with edge 0 of the reference element.