size of KERNEL (1..n) in splin[es].c

[alle_meije]

Hi,

I am managing code that I have not written myself, which calls the routines spline() and splins(). The integer n (3rd argument to spline, 4th to splins) is defined as KERNEL = 4.

Could KERNEL, or n, be anything else than 4 for cubic splines? I would guss that it could not be less than 4, but for multidimensional data, it could be as large as dim[i] for which ever dimension you want to interpolate, couoldn't it?

I tried to find references in the book and on the internet, but there are no real explanations as to what values n can take.

Thanks for your help!