Incorrect Jacobian indexing in Nedelec DOF basis transformation

[Ady0333]

Describtion

In TransformNedelecDofBasis.evaluate! (src/FESpaces/CurlConformingFESpaces.jl), the Jacobian array Jtx is indexed using the local loop index p instead of the global node index from dofs.face_nodes[face].

Current code:

F = transpose(Jtx[p])

But p is only a local index on the face, while Jtx is indexed globally over all DOF quadrature points in the cell.

For faces beyond the first, this ends up using the Jacobian from a wrong quadrature point during the Piola transform of the DOF moments.

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Expected behavior

The Jacobian should be accessed using the corresponding global node index:

F = transpose(Jtx[face_point_ids[p]])

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Impact

This affects H(curl) (Nedelec) elements on non-affine meshes (e.g. quads/hexes or curved geometries), where the Jacobian varies within the cell.

It can lead to incorrect DOF basis transformation and wrong assembled system matrices without any runtime error.

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Affected File

src/FESpaces/CurlConformingFESpaces.jl