ljd.m

de Boor 求值算法求作二次和三次B-样条插值曲线

function u=LJD(n,k,x,y,z)
%使用累加弦长法确定节点矢量
%该算法取两端点节点重度r=k，即首末控制点就是首末数据点
u=zeros(1,n+2*k-2);
for i=1:n-1    
    L(i)=sqrt((x(i+1)-x(i))^2+(y(i+1)-y(i))^2+(z(i+1)-z(i))^2);
end
for i=1:k
    u(i)=0;
end
for i=k+1:n+k-1
    u(i)=u(i-1)+L(i-k);
end
for i=n+k:n+2*k-2
    u(i)=u(i-1);
end