A few models in the zoo require installation of the NetLogo R extension. This extension is available from here and is described in
Thiele JC, Grimm V. 2010. NetLogo meets R: Linking agent-based models with a toolbox for their analysis. Environmental Modelling and Software 25(8), 972-974.
This extension requires installation of the R system for statistical computing available here.
Installation of this extension may be quite involved on some systems, since it depends on details of both your NetLogo installation and your R installation. In particular installation may involve setting some environment variables to ensure that NetLogo and the version of R that NetLogo is using are accessing compatible versions of the Java virtual machine.
After installation, you will find detailed instructions for configuring the installation in the doc subfolder of the r extension folder in your NetLogo extensions folder. Follow them carefully. If you run into problems, you should seek help from the R extension development team.