In this post, I describe how to use the reshape package to modify a dataframe from a long data format, to a wide format, and then back to a long format again. It’ll be an epic journey; some of us may not survive (especially me!). Wide versus Long Data Formats I’ll begin by describing what 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
