数学建模与数学实验（第3版）课件+matlab

				x0=[0 3 5 7 9 11 12 13 14 15 ];
				y0=[0 1.2 1.7 2.0 2.1 2.0 1.8 1.2 1.0 1.6 ];
				x=0:0.1:15;
				y1=lagr1(x0,y0,x);
				y2=interp1(x0,y0,x);
				y3=interp1(x0,y0,x,'spline');
				subplot(3,1,1)
				plot(x0,y0,'k+',x,y1,'r')
				grid
				title('lagrange')
				subplot(3,1,2)
				plot(x0,y0,'k+',x,y2,'r')
				grid
				title('piecewise linear')
				subplot(3,1,3)
				plot(x0,y0,'k+',x,y3,'r')
				grid
				title('spline')