Reaggregation tool for translating historical data to current boundaries.
Reag will use data for counties whose boundaries have not changed directly. For all other counties, it will determine the geometric intersection between year 2000 county boundaries and historical boundaries, and compute estimated values from each historical county contribution.
Reag uses Python 2.6+, pyshp, and shapely.
Follow the instructions on https://github.com/GeospatialPython/pyshp and http://toblerity.org/shapely/project.html#installation to install these dependencies.
python getvalues.py <historical-shapefile> <values-csv> <values-column> <type>
The historical shapefile and values csv must represent the same year. type may be SUM or AVG.
For example,
python getvalues.py nhgis0005_shapefile_tl2000_us_county_1950/US_county_1950 nhgis0001_ts_1950_county.csv A00AA1950 sum
Reag will display the reaggregated results, in CSV format with the FIPS, state name, county name, and value. You may want to pipe this to an output file (python getvalues.py ... > output.csv).
The final result takes about an hour to generate, for a moderate number of county changes.