检查下列代码并改正function S=csfit XYdx0dxnN=length X-1;H=diffX;D=diff YH;A=H2N-1;B=2H1N-1+H2N;C=H2N;U=6diffD;B 1=B1-H12;U1=U1-3D1;BN-1=BN-1-HN2;UN-1=UN-1-3-D N;for k=2N-1temp=A k-1Bk-1;Bk=Bk-tempCk-1;Uk=Uk-te

function S = csfit(X, Y, dx0, dxn) N = length(X)-1; H = diff(X); D = diff(Y)./H; A = H(1:N-2); B = 2*(H(1:N-1)+H(2:N)); C = H(2:N-1); U = 6diff(D); B(1) = B(1) - H(1)/2; U(1) = U(1) - 3D(1); B(N-1) = B(N-1) - H(N)/2; U(N-1) = U(N-1) - 3*(-D(N)); for k = 2:N-1 temp = A(k-1)/B(k-1); B(k) = B(k) - tempC(k-1); U(k) = U(k) - tempU(k-1); end M(N) = U(N-1)/B(N-1); for k = N-2:-1:1 M(k+1) = (U(k) - C(k)M(k+2))/B(k); end M(1) = 3(D(1)-dx0)/H(1) - M(2)/2; M(N+1) = 3*(dxn-D(N))/H(N) - M(N)/2; S = zeros(N, 4); for k = 1:N S(k, 1) = (M(k+1)-M(k))/(6H(k)); S(k, 2) = M(k)/2; S(k, 3) = D(k) - H(k)(2*M(k)+M(k+1))/6; S(k, 4) = Y(k); end en