[PD] better tabread4~
matju at artengine.ca
Wed Jul 2 12:29:49 CEST 2008
On Sat, 28 Jun 2008, Matt Barber wrote:
> It's also bad because while a natural cubic spline is conceivable for a
> tabread (fixing the 2nd derivative to zero on both ends, reading in and
> keeping all the derived data in a buffer somewhere), you might need a
> different kind of spline (periodic?) for a tabosc~
Yes, the periodic version of the natural cubic spline doesn't have 2nd
derivative constraints on endpoints, and instead matches the 1st
derivatives of both ends together. It's a small change in one way, but
it's not in another, because you can't use the shortcuts associated with
> and it shouldn't work at all for a vd~ since there is no codified
> beginning or end to the table (yes-no?).
Right. But actually, it's not really useful to go on about this, it was
just a mistake of mine because I misread a page.
> Which is equivalent to the slope between the 2-sample gap. This would
> have another advantage over forward- or backward-differences such that
> going through the table in reverse would produce a symmetric result.
> (or actually, would it matter after all, since the four points are in
> the same order whether you're going forward or backward through the
> table... ?)
This is not the reason, it's because people have more-or-less-defined
expectations about an interpolator, and if one assumes symmetricity
because of a sample that has been flipped backwards and it introduces a
1-delay sample... one got to know... maybe.
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| Mathieu Bouchard - tél:+1.514.383.3801, Montréal, Québec
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