数学建模与数学实验（第3版）课件+matlab

				function y=lagr1(x0,y0,x)
				n=length(x0); m=length(x);
				for i=1:m
				   z=x(i);
				   s=0.0;
				   for k=1:n
				      p=1.0;
				      for j=1:n
				         if j~=k
				            p=p*(z-x0(j))/(x0(k)-x0(j));
				         end
				      end
				      s=p*y0(k)+s;
				   end
				   y(i)=s;
				end