Miller Puckette escribió:
The tabread4~ algorithm is to put a cubic through the 4 points surrounding the input point. However, this cubic curve does not necessarily match the next curve over in first derivative.
Oh I see! I thought it did. I confuded that technique with natural cubic splines :$
Now I remember that in order to compute the coefficients for a cspline you have to know in advance all the points of the table (iirc). But the general formula for csplines doesn't assume equally spaced points...
So now i dubt is it possible at all to find the piecewise cubic that ensures continuity of the 1st and 2nd derivatives by using 4 points at a time? (at least in the case of equally spaced points)
thanks m.