function C = lspoly(X,Y,M)%Input   - X is the 1xn abscissa vector%        - Y is the 1xn ordinate vector%        - M is the degree of the least-squares polynomial% Output - C is the coefficient list for the polynomial%  NUMERICAL METHODS: Matlab Programs% (c) 2004 by John H. Mathews and Kurtis D. Fink%  Complementary Software to accompany the textbook:%  NUMERICAL METHODS: Using Matlab, Fourth Edition%  ISBN: 0-13-065248-2%  Prentice-Hall Pub. Inc.%  One Lake Street%  Upper Saddle River, NJ 07458n=length(X);B=zeros(1:M+1);F=zeros(n,M+1);%Fill the columns of F with the powers of Xfor k=1:M+1   F(:,k)=X'.^(k-1);end%Solve the linear system from (25)A=F'*F;B=F'*Y';C=A\B;C=flipud(C);