Efficient spanning trees for a high-order edge element T-Ψ eddy current formulation

The use of spanning trees is discussed for a high-order hexahedral edge element method, for a source field computation method, and for the voltage forcing method. The first represents a generalization of the co-tree gauge, the second represents an efficient method for finding source fields, and for the voltage forcing method, it is demonstrated that a source field found using the right spanning tree results in a large reduction in CPU-time for solving the main (eddy current) equation system.