*After the calculations, this record will be filled with the ratio
of the the internal forces (out-of-balance forces) and the external forces.
The internal forces are taken from the post_node_rhside_free record.
The external forces are taken from the post_node_rhside_fixed record.
The maximum ratio for the unknowns is used.
*

*As an expeption, if the external forces are very low (below 1.e-6),
the ratio is directly filled with the internal forces and so
represent an absolute value of unbalance and no unbalance ratio.
*

*See also post_node_rhside_ratio_unknowntypes.
*

tochnog 2001-09-02