Evaluating districting plans in the real world
GerryChain is used to analyze redistricting plans in the real world. For example, it’s been used in states ranging from Pennsylvania to North Carolina to Wisconsin for defend civil rights. So, MGGG has developed a toolkit of functions for use to analyze a redistricting plan. Here, we will describe these tools and how they are used to analyze real-world districting plans.
gerrytools
gerrytools is a toolkit that contains:
a suite of plan scoring metrics (like efficiency gap and reock scores) for use in comparing plans
a suite of data grabbing/manipulating tools, with an emphasis on interacting with Census data
super-easy and beautiful visualization functions to make pretty graphs and intuitive displays of data
miscellaneous things we find useful
It also has fairly good documentation, which you can read here: https://mggg.github.io/gerrytools/
PyEI
PyEI is a ecological inference package in Python that is intended for racial polarized voting analysis. This analysis is required for Voting Rights Act challenges of gerrymandered redistricting maps. As such, PyEI is essential to MGGG’s work.
Other tools
There are also other tools maintained by MGGG, including maup and pcompress, which have their own set of documentation.