Matt Barber escribió:
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..
Hmm, by linear I mean that the interpolated version of the sum of any two discrete signals is equal to the sum of the interpotated versions of each one. It shouldn't be difficult to tell whether this is true or not by looking at the formulas but I'm too lazy right now :P
If the transformation is not linear, then there is no "impulse response" at all nor any "frequency response" strictly speaking, thought that doesn't mean that it doesn't make sense to do some reasoning in terms of impulse or frequency response under certain simplifications or assumptions - i.e. to speak less strictly....
-- Matteo Sisti Sette matteosistise...@gmail.com http://www.matteosistisette.com _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
