Did you have a look at Dynamic Time Warping and dtw package? Best, E.
On Mon, May 27, 2013 at 01:34:42PM +0200, Lorenzo Isella wrote: > Dear All, > Apologies for not posting a code snippet, but I really need a pointer about > a methodology to look at my data and possibly some R package which can ease > my task. > I am given a set consisting of several multivariate noisy time series, > let's call it {A}. > Each A_i in {A}, in turn, consists of several numerical time series. > Then I have another set of shorter time series {B}. > Now, for every B_j in {B}, I need to determine the time series A_i where > most likely B_j comes from (A_i is not just a subset of B_j). > In other words, I need to determine the distance between A_i and B_j. > I was thinking about the Mahalanobis distance described here. > > http://en.wikipedia.org/wiki/Mahalanobis_distance > > However, I have several questions in my head > 1) With the Mahalanobis distance, do I lose the info about the time > structure of the data? I am not just comparing some distributions, but some > time series and the ordering of the data is important. > 2) Even if the use of the Mahalanobis distance was appropriate, it involves > the calculation of a covariance matrix and a mean. > Should I average A_i or B_j (or a subset of B_j having the same length as > A_i)? And should I use a correlation matrix based on A_i or B_j? > > Any suggestion is welcome. > > Lorenzo > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.