Statistics – Machine Learning
Scientific paper
2011-01-04
Statistics
Machine Learning
Scientific paper
We propose in this work a new family of kernels for variable-length time series. Our work builds upon the vector autoregressive (VAR) model for multivariate stochastic processes: given a multivariate time series x, we consider the likelihood function p_{\theta}(x) of different parameters \theta in the VAR model as features to describe x. To compare two time series x and x', we form the product of their features p_{\theta}(x) p_{\theta}(x') which is integrated out w.r.t \theta using a matrix normal-inverse Wishart prior. Among other properties, this kernel can be easily computed when the dimension d of the time series is much larger than the lengths of the considered time series x and x'. It can also be generalized to time series taking values in arbitrary state spaces, as long as the state space itself is endowed with a kernel \kappa. In that case, the kernel between x and x' is a a function of the Gram matrices produced by \kappa on observations and subsequences of observations enumerated in x and x'. We describe a computationally efficient implementation of this generalization that uses low-rank matrix factorization techniques. These kernels are compared to other known kernels using a set of benchmark classification tasks carried out with support vector machines.
Cuturi Marco
Doucet Arnaud
No associations
LandOfFree
Autoregressive Kernels For Time Series does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Autoregressive Kernels For Time Series, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Autoregressive Kernels For Time Series will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-74479