%---------------------------Aspect Frobenius-----------------------------
\section{Aspect Frobenius\label{s:tet-aspect-Frobenius}}

The edge matrix of the tetrahedral element is defined as
follows:
\[
T_0 = (\vec{L_0}\;\vec{L_1}\;\vec{L_2})
\]
and let $W$ be the edge matrix of the reference regular tetrahedron.
Consider the matrix that maps $W$ into $T_0$:
\[
A_0 = T_0 W^{-1}.
\]
The Frobenius norm of $A_0$ is
\[
|A_0|_F = \sqrt{\mathrm{tr}(A_0^T\, A_0)},
\]
and the Frobenius condition number is the condition number associated
with this norm.

The aspect Frobenius of the element is defined as the normalized
(equal to $1$ when the element is regular) Frobenius condition number of $A_0$.

\tetmetrictable{aspect Frobenius}%
{$1$}%                                                Dimension
{$[1,1.3]$}%                                          Acceptable range
{$[1,DBL\_MAX]$}%                                     Normal range
{$[1,DBL\_MAX]$}%                                     Full range
{$1$}%                                                Unit equilateral triangle value
{\cite{knu:00}}%                                      Reference(s)                   
{v\_tet\_aspect\_frobenius}%                            Verdict function name