[PD] tabread4~ "broken" interpolation algorithm - was Re:, Max Smoother Audio than Pd?

[Matt Barber]

Yes, as far as I know it's identical -- when you do one of these
interpolations with four points, you can either think of it in terms
of a cubic polynomial formula involving those four points, or in terms
of the sum of four scaled "basis functions" - the latter seems to me
intuitively equivalent to direct convolution of an impulse response
centered on the four points, and scaled to each.  It will be limited
by the quantization of the index, so in that sense it might not be
linear..

MB

On Tue, Mar 30, 2010 at 6:45 AM, Matteo Sisti Sette
<matteosistisette at gmail.com> wrote:
> Is it really possible to express a cubic interpolator (such as Lagrange or
> Hermite, i.e. such as tabread4 or tabread4c) in terms of impulse response?
> Is it equivalent to a convolution? That is to ask: is it linear???
> Or is that an approximation?
>
> --
> Matteo Sisti Sette
> matteosistisette at gmail.com
> http://www.matteosistisette.com
>