The program determines shear line rigidity K for rigid diaphragm analysis by summing the rigidities of all segments along the line, i.e.
K = S Fi/DI,
where Fi and DI, are the forces and deflections on each segment. If forces are also distributed within the line based on deflection, so that deflections are equalised , this is just F/D, the total force over the common deflection.
Change to Manual Input
If you change the setting from Use shear wall deflection to calculate rigidity to Manual input of relative rigidity, in order to adjust the rigidities, the rigidities that appear in the input for a particular wall are the sum of the rigidities for all segments along the wall, divided by the wall length.