Efficient and Robust Polylinear Analysis of Noisy Time Series

A method is proposed to generate an optimal fit of a number of connected linear trend segments onto time-series data. To be able to efficiently handle many lines, the method employs a stochastic search procedure to determine optimal transition point locations. Traditional methods use exhaustive grid searches, which severely limit the scale of the problems for which they can be utilized. The proposed approach is tried against time series with severe noise to demonstrate its robustness, and then it is applied to real medical data as an illustrative example.