[Scilab-users] Bessel cubic spline

[Pinçon Bruno]

Le 26/02/2017 à 12:49, fujimoto2005 a écrit :
> Is there a function of Bessel cubic spline?
> I mean Besse cubic spline as follows.
> 1,pieacewise 3 degree polynomial on the each interval [x(i),x(i+1)] for
> i=1,2,..,n-1
> 2,f(x(i))=y(i) for 1=1,2,..,n
> 3,continuous at all xi for i=2,...,n-1
> 4,differnciable at all xi for i=2,...,n-1
> 5,f''(xi) for i=2,...,n-1 is same as the slope of a quadratic function which
> pass 3 points (x(i-1),y(i-1)) (x(i),y(i)),(x(i+1),y(i+1))
> 5,f''(x(1))is same as the slope of a quadratic function which pass 3 points
> (x(1),y(1)) (x(2),y(2)),(x(3),y(3))
> 5,f''(x(n))is same as the slope of a quadratic function which pass 3 points
> (x(n-2),y(n-2)) (x(n-1),y(n-1)),(x(n),y(n))
>

     Hello,

    this is the option "fast" of the splin function (use splin to compute
   the spline and interp to evaluate it at some points).

    hth
  Bruno