Linearizing electric fields with first order finite element potential solutions

Using first order triangular finite elements, the electric field values are constant in each element all over the mesh. This aspect introduces discretization errors that might be significant, and does not allow the plot of isolines of the electric field. The paper presents two algorithms developed and tested by the authors to overcome the previous difficulties, which transform the constant electric field values into linear ones. Discontinuities arising from the use of different permittivity materials are taken into account. The proposed methodologies are also applicable to other quantities besides the electric field, such as magnetic induction