/**
- * A finite element, which is a tensor product polynomial on each face and
+ * A finite element that is a tensor product polynomial on each face and
* undefined in the interior of the cells. The basis functions on the faces
* are Lagrange polynomials based on the support points of the
* (dim-1)-dimensional Gauss--Lobatto quadrature rule. For element degree one
* demonstrated in the step-51 tutorial program.
*
* @note Since this element is defined only on faces, only FEFaceValues and
- * FESubfaceValues will be able to extract reasonable values from any face
- * polynomial. In order to make the use of FESystem simpler, using a (cell)
- * FEValues object will not fail using this finite element space, but all
- * shape function values extracted will be equal to zero.
+ * FESubfaceValues will provide useful information. On the other hand, if you
+ * use this element with FEValues for cell integration, then the values
+ * and derivatives of shape functions will have invalid values and will not
+ * likely produce anything useful. In order to make the use of this element
+ * as part of an FESystem simpler, using a (cell) FEValues object will not fail
+ * outright, but those components of shape functions of the combined element
+ * that correspond to FE_FaceQ will have the invalid values mentioned above.
*
* @ingroup fe
* @author Guido Kanschat, Martin Kronbichler
/**
- * A finite element, which is a Legendre element of complete polynomials on
+ * A finite element that is a Legendre element of complete polynomials on
* each face (i.e., it is the face equivalent of what FE_DGP is on cells) and
* undefined in the interior of the cells. The basis functions on the faces
* are from Polynomials::Legendre.
* hybridizes methods can be found in the step-51 tutorial program.
*
* @note Since this element is defined only on faces, only FEFaceValues and
- * FESubfaceValues will be able to extract reasonable values from any face
- * polynomial. In order to make the use of FESystem simpler, using a (cell)
- * FEValues object will not fail using this finite element space, but all
- * shape function values extracted will be equal to zero.
+ * FESubfaceValues will provide useful information. On the other hand, if you
+ * use this element with FEValues for cell integration, then the values
+ * and derivatives of shape functions will have invalid values and will not
+ * likely produce anything useful. In order to make the use of this element
+ * as part of an FESystem simpler, using a (cell) FEValues object will not fail
+ * outright, but those components of shape functions of the combined element
+ * that correspond to FE_FaceP will have the invalid values mentioned above.
*
* @ingroup fe
* @author Martin Kronbichler
/**
* FE_FaceP in 1D, i.e., with degrees of freedom on the element vertices.
+ * See the documentation of the general template for more information.
*/
template <int spacedim>
class FE_FaceP<1,spacedim> : public FE_FaceQ<1,spacedim>