I'm glad to inform that I already have a very very (once again very!) rough version of the DTW object. It's already measuring the distance between two series of numbers - although I have some doubts about the inlets, if I should receive the values as an array or list (currently list, because I didn't knew how to manipulate arrays - this is my first external).

I should post a alpha version when the code is more cleaned up. The implementation of the DTW iteself is based on Andrew Slater/John Coleman's code.

best regards,
Pedro

On Fri, Apr 30, 2010 at 6:39 PM, Pedro Lopes <pedro.lopes@ist.utl.pt> wrote:
Hello,  I'm trying to do a small project, for which I need an implementation of the DTW [1] (Dynamic Time Warping) algorithm. It takes to series of values and measures the similarity between them, considering that they can vary time or speed.

I've done a few searches but seems to be impossible to find a DTW external for Pd, is there one?

On the SMC2009 conference, a paper[2] was presented where they stated that they used DTW under Pd but I couldn't find their implementation anywhere (nor received feedback from the authors still). Also there is a reference to a Max/MSP implementation by Olaf Matthes [3] but once again... cannot find a Pd version.

So if anyone can be of help in this search for DTW inside Pd, it would be most helpful. 

p.s.: As far as C alike implementations, I found this in C [4] and this C++ lib [5] seems to use a DTW implementation too.

[1] http://en.wikipedia.org/wiki/Dynamic_time_warping
[2] http://smc2009.smcnetwork.org/programme/pdfs/321.pdf
[3] http://maxobjects.com/?v=authors&id_auteur=39



--
Pedro Lopes
contacto: jazz@radiozero.pt
website: http://web.ist.utl.pt/Pedro.Lopes



--
Pedro Lopes
contacto: jazz@radiozero.pt
website: http://web.ist.utl.pt/Pedro.Lopes