% Illustration of the "constant block" introduced for "inverting" % non-invertible LFR-objects. Normalization and converse. S = rlfr(5,3,3,2,2,'d'); S.d = zeros(3,3); % "Inversion" of the non-invertible LFR-object invS = inv(S); size(invS) % The second line displayed by the function size shows that the % dummy parameter is repeated 3 times in a block named "constant % block". % Modification of the bound information. Here, the nominal value (4) % is not centered in the range of variations ([2 8]) set(invS,{'d1','d2'},{[2 8 4],[2 8 4]},{'minmax','minmax'}); size(invS) % The function 'set' changes the bound information stored in the % LFR-object but bo not modify numerical values. For updating the % nominal value, the function normalizelfr must be invoked. invS2 = normalizelfr(invS); % Inversion is feasible now, therefore the dummy parameter has % disappeared as shown below size(invS2) % Note that it is possible to compute the actual values of parameters % from normalized ones. par_nom = [-0.5 0.5]; par_act = actualval(invS2,{'d1','d2'},par_nom) % uplft(invS,{'d1','d2'},par_act) and uplft(invS2,{'d1','d2'},par_nom) % are equal. % The system invS2 can be unnormalized distlfr(invS,unnormalize(invS2))