Spline DEMO

Demonstratie cu spline cubice

Contents

Alegem functia $f(x)=\cos x$ si nodurile $0,\pi/2, \pi, 3\pi/2, 2\pi$

f = @(x) cos(x);
d=-sin([0,2*pi]);
t=linspace(0,2*pi,200)';
x=[0,pi/2,pi,3*pi/2,2*pi]; y=f(x);

Spline complete

[a1,b1,c1,d1]=Splinecubic(x,y,0,d);
s1=valspline(x,a1,b1,c1,d1,t);

spline cu derivate secunde

d2=-cos([0,2*pi]);
[a2,b2,c2,d2]=Splinecubic(x,y,1,d2);
s2=valspline(x,a2,b2,c2,d2,t);

spline naturale

[a3,b3,c3,d3]=Splinecubic(x,y,2);
s3=valspline(x,a3,b3,c3,d3,t);

spline deBoor

[a4,b4,c4,d4]=Splinecubic(x,y,3);
s4=valspline(x,a4,b4,c4,d4,t);

reprezentare grafica

yg=f(t);
plot(x,y,'o',t,[yg,s1,s2,s3,s4])
legend('noduri','f','complet','d2','natural','deBoor','Location','BestOutside')