x=[0.2:0.2:1.0];
y=[0.98 0.92 0.81 0.64 0.38];
x=[1:1:10]；
y=[2:2:20]；
pp=interp1(x,y,'spline','pp')
breaks=pp.breaks
coefs=pp.coefs
>> x=[0.2:0.2:1.0];
y=[0.98 0.92 0.81 0.64 0.38];
>> pp=spline(x,y)
>> pp.coefs
ans =
-0.1042 -0.5625 -0.1833 0.9800
-0.1042 -0.6250 -0.4208 0.9200
-0.7292 -0.6875 -0.6833 0.8100
-0.7292 -1.1250 -1.0458 0.6400
返回的是三次样条插值档大函数每段的系数，三次行轮竖样条插值每段是三次桐咐多项式。
clc
clear
x=[0.2:0.2:1.0];
y=[0.98 0.92 0.81 0.64 0.38];
figure(3)
plot(x,y)
hold on
P=spline(x,y);
Y=ppval(P,x);
plot(x,Y,'k')
hold off
=[0.2:0.2:1.0]; y=[0.98 0.92 0.81 0.64 0.38];