Similar expressions can be derived for the T<sup>(EM)</sup>, U<sup>(HJ)</sup> and Y<sup>(HM)</sup>elements of the MoM matrix.
== Discretization Of of Electric & Magnetic Currents ==
The right choice of the basis functions to represent the elementary currents is very important. It will determine the accuracy and computational efficiency of the resulting numerical solution. Rooftop basis functions are one of the most popular types of basis functions used in a variety of MoM formulations. The surface currents (whether electric or magnetic) are discretized using 2D rooftop basis functions shown in the figure below:
<table><tr><td> [[File:image055_tn.png]]Â |thumb|480px|Rooftop or RWG basis functions built over two rectangular, triangular or mixed cells.]] </td> </tr></table>
The rooftop basis functions are defined over two adjacent cells with a common edge of length. If the two cells are triangular, then the so-called RWG functions are obtained. It is also possible to define rooftop functions over two adjacent rectangular cells or two adjacent rectangular and triangular cells with a common edge. On a rectangular cell, the function is defined as having a (descending or ascending) linear profile in one direction and a constant profile in the other perpendicular direction.
[[File:image065_tn.png]][[File:image066_tn.png]]
<table>
<tr>
<td> [[File:image065_tn.png|thumb|480px|Prismatic basis functions built over single triangular and rectangular cells.]] </td>
</tr>
</table>
Prismatic basis functions built over single triangular and rectangular cells.