how to change the distance in fuzzy C-Means with similarity parameter

while (EPSI>MIN)&(P<8); for ii=1:c for x=1:aa for y=1:bb DF=0;

                D=(sqrt(sum((DD(:,x,y)-C(:,ii)).^2))); /// distance
                for jj=1:c
                    D1=(sqrt(sum((DD(:,x,y)-C(:,jj)).^2))); /// distance
%                     size(D1)
                    DF=DF+((D/D1)^(2/(m-1)));
                end;
                U(ii,x,y)=1/DF;
            end;
        end;
    end;