Tuesday, February 26, 2013

Week 7: Applied Time-Series Analysis for Fisheries and Environmental Data

Class material: webpage

Week 7: Dynamic factor analysis

This week, we use MARSS to do dynamic factor analysis (DFA), which allows us to look for a set of common underlying trends among a relatively large set of time series (Harvey, 1989, sec. 8.5). This is conceptually different than what we have been doing in the previous weeks. Here we are trying to explain temporal variation in a set of n observed time series using linear combinations of a set of m hidden random walks, where m << n. You can think of this as PCA for time-series data. Zuur et al. (2003) show a number of examples of DFA applied to catch data and densities of zoobenthos.

Lab 7
The main lab is to go through the dynamic factor analysis chapter in the MARSS User Guide and the corresponding code.

Lecture 7
You can find the ppt of lecture on the class webpage. Technical difficulties prevented recording of the lecture.

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