functionC4=C4f(epsi,C4x)%C4F Evaluate C_4%% C4 = C4F(epsi, C4x) evaluates C_{4,l} in the expansion for the area% (Eq. (65) expressed in terms of n and epsi) using the coefficient% vector C4x. epsi is a K x 1 array. C4x is a 1 x 21 array. C4 is a% K x 6 array.nC4=6;C4=zeros(length(epsi),nC4);mult=1;o=1;forl=0:nC4-1m=nC4-l-1;C4(:,l+1)=mult.*polyval(C4x(o:o+m),epsi);o=o+m+1;mult=mult.*epsi;endend