| function [kappa, ccurv] = curv_centre(C) | |
| d = size(C, 1); % Dimensió de l'ambient | |
| % Arestes | |
| ar01 = C(:, 2:end-1) - C(:, 1:end-2); | |
| ar12 = C(:, 3:end) - C(:, 2:end-1); | |
| % Mètrica | |
| g11 = sum(ar01.*ar01); | |
| g12 = sum(ar01.*ar12); | |
| g22 = sum(ar12.*ar12); | |
| % Centres de curvatura | |
| detG = g11.*g22 - g12.*g12; | |
| lambda1 = (0.5*g11.*g22 - g12.*g12 - 0.5*g12.*g22)./detG; | |
| lambda2 = (0.5*g11.*g12 + 0.5*g11.*g22)./detG; | |
| ccurv = C(:, 1:end-2) + (ones(d, 1)*lambda1).*ar01; | |
| ccurv = ccurv + (ones(d, 1)*lambda2).*ar12; | |
| % Curvatura com a invers del radi | |
| vradi = C(:, 1:end-2) - ccurv; | |
| radi = sqrt(sum(vradi.*vradi)); | |
| kappa = 1./radi; |