newton interpolation (牛顿多项式插值法)

%% Run in this .mFile %% f(x)=sin(x) x = -5:5; y = sin(x); p = NewtonInterpolate(x,y);% get interpolation polynomial of sin(x) x = -5:0.1:5; % in order to get a smooth figure, the step value is 0.1 y = p(x); figure(1); plot(x,y,'r','LineWidth',2);hold on % interpolation polynomial plot(x,sin(x),'--b','LineWidth',2); % original function title('f(x)=sin(x)'); legend('Original Function','NewTon Interpolate Function'); grid on %% f(x)=1/(1+x*x) x = -5:5; y = 1./(1+x.*x); p = NewtonInterpolate(x,y); % get interpolation polynomial of 1/(1+x*x) x = -5:0.1:5; y = p(x); figure(2); plot(x,y,'r','LineWidth',2);hold on % interpolation polynomial plot(x,1./(1+x.*x),'--b','LineWidth',2); % original function title('f(x)=1/(1+x*x)'); legend('Original Function','NewTon Interpolate Function'); grid on