This is the code is associated with the article: Boker, S. M., Deboeck, P. R., Edler, C. & Keel, P. K. (2009). Generalized Local Linear Approximation of Derivatives from Time Series. In S. Chow, E. Ferrer & F. Hsieh (Eds.), Statistical Methods for Modeling Human Dynamics: An Interdisciplinary Dialogue. Lawrence Erlbaum Associates.