This sets, for either the geometry_line or the geometry_triangle or the geometry_quadrilateral with the same index extra factors which are used for the bounda_unknown and the bounda_force records. The boundary conditions at a node being part of the geometrical entity are multiplied with the interpolation of the factors. For a geometry_line either 2 or 3 factors should be specified; 2 factors define a linear variation where the factors hold at the start and end of the line respectively; 3 factors define a parabolic variation where the factors hold at the start, at the middle and at the end of the line respectively. For a geometry_triangle 3 factors should be specified (a linear variation with factors for the first, second and third corner point respectively). For a geometry_quadrilateral 4 factors should be specified (a linear variation with factors for the first, second, third and fourth corner point respectively). In the example below, node 2 will get temperature and node 3 will get temperature .
node 2 0.2 0
node 3 0.4 0.
geometry_line 1 0. 0. 1. 0. 0.01
geometry_bounda_factor 1 1. 4.
bounda_unknown 0 -geometry_line 1 -temp
bounda_time 0 0. 20. 1.e6 20.