BE_n()

normal with respect to a boundary element

Computes the normal of a boundary element of a fixed boundary, e.g. of a triangle. As the function needs to return a scalar, the x-, y-, or z-component of the normal is selected by providing 1, 2, or 3 as argument, respectively. This is useful when used together with BEsum() in the context of MOVE statements or within a BE_MONITOR_ITEM or SAVE_BE_MONITOR_ITEM. Example:

begin_equation{$normal_x$} BE_n(1) end_equation begin_equation{$normal_y$} BE_n(2) end_equation begin_equation{$normal_z$} BE_n(3) end_equation