Multi-order vector finite element modeling of 3D magnetotelluric data including complex geometry and anisotropy

Earth, Planets and Space

Table 2 Time and memory used in multi-order VFEM with GPML-II boundary conditions (Zhou et al. 2012)

Element	Linear	Quadratic	Lagrangian
Grid \(N_\text{e}\)	\(62\times 62\times 47\)	\(26\times 26\times 20\)	\(26\times 26\times 20\)
DoF	561,519	172,680	338,352
NNZE	9,291,615	6,979,448	17,158,968
Assembly time	184.55 s	389.12 s	770.37 s
Total time	8046.82 s	2603.16 s	3877.8 s
\(\epsilon ^{\text{avg}}_\rho\)	\(12.77\%\)	\(0.26\%\)	\(0.22\%\)
\(\epsilon ^{\text{avg}}_\phi\)	\(3.29\%\)	\(2.3\%\)	\(2.3\%\)

Times are shown in seconds, and the memory is presented in terms of the number of elements \(N_\text{e}\), the number of unknowns (DoF) and the number of non-zero entries for the global array NNZE. Average errors are shown for resistivity \(\epsilon ^{\text{avg}}_\rho\), and for the phase \(\epsilon ^{\text{avg}}_\phi\)