ex1602.m

数字信号处理的MATLAB实现

%例16-2 其他几种方法对sin函数进行插值
x = 0:10;
y = sin(x);
xi = 0:.25:10;
yi=sin(xi);
y1=interp1(x,y,xi,'nearest');
y2=interp1(x,y,xi,'spline');
y3=interp1(x,y,xi,'cubic');
grid on
plot(x,y,'o',xi,yi,xi,y1,'-.')	%最邻近插值，如图16-2
plot(x,y,'o',xi,yi,xi,y2,'-.')	%三次样条插值，如图16-3
plot(x,y,'o',xi,yi,xi,y3,'-.')	%三次多项式插值，如图16-4