force_element_edge_normal_factor index $a_0$ $a_1$ ...$a_n$

This data item defines a polynomial in space. This polynomial gives a factor which is used as a multiplication factor for force_element_edge_normal records (with the same index). In this way, you can obtain coordinate dependent forces.

In 1D the polynomial is $a_0 + a_1 x + a_2 x^2 + \ldots$. In 2D the polynomial is $a_0 + a_1 x + a_2 y + a_3 x^2 + a_4 xy + a_5 y^2 + a_6 x^3 + a_7 x^2 y + a_8 x y^2 + a_9 y^3 + \ldots$. In 3D the polynomial is $a_0 + a_1 z + a_2 z^2 + \ldots$.