# Chapter 10 Dynamic Factor Analysis

Here we will use the MARSS package to do Dynamic Factor Analysis (DFA), which allows us to look for a set of common underlying processes among a relatively large set of time series (Zuur et al. 2003). There have been a number of recent applications of DFA to ecological questions surrounding Pacific salmon (Stachura, Mantua, and Scheuerell 2014; Jorgensen et al. 2016; Ohlberger, Scheuerell, and Schindler 2016) and stream temperatures (Lisi et al. 2015). For a more in-depth treatment of potential applications of MARSS models for DFA, see Chapter 9 in the MARSS User’s Guide.

A script with all the R code in the chapter can be downloaded here. The Rmd for this chapter can be downloaded here.

### Data and packages

All the data used in the chapter are in the MARSS package. Install the package, if needed, and load to run the code in the chapter.

library(MARSS)