functionC2=C2f(epsi)%C2F Evaluate C_{2,k}%% C2 = C2F(epsi) evaluates C_{2,l} using Eq. (43). epsi is a K x 1 array% and C2 is a K x 6 array.persistentcoeffnC2ifisempty(coeff)nC2=6;coeff=[...1,2,16,32,...35,64,384,2048,...15,80,768,...7,35,512,...63,1280,...77,2048,...];endC2=zeros(length(epsi),nC2);eps2=epsi.^2;d=epsi;o=1;forl=1:nC2m=floor((nC2-l)/2);C2(:,l)=d.*polyval(coeff(o:o+m),eps2)/coeff(o+m+1);o=o+m+2;d=d.*epsi;endend