These are non-directed dyad-year data for the minimum distance between states in the Gleditsch-Ward state system from 1886 to 2019. The data are generated from the cshapes package.
gw_mindistA data frame with 868813 observations on the following 4 variables.
gwcode1the Gleditsch-Ward state system code for the first state
gwcode2the Gleditsch-Ward state system code for the second state
yearthe year
mindistthe minimum distance between states on Jan. 1 of the year, in kilometers
Data are automatically generated (by default) as directed dyad-years. I elect to make them non-directed for space considerations. Making non-directed dyad-year data into directed dyad-year data isn't too difficult in R. It just looks weird to see the code that does it.
Previous versions of these data were for the minimum distance as of Dec. 31
of the referent year. These are now Jan. 1. Most of the data I provide
elsewhere in this package are to be understood as the data as they were at
the start of the year. add_minimum_distance() permits greater flexibility
with this option, but only for the remote and augmented version of the data.
Check the documentation of that function for more.
Schvitz, Guy, Luc Girardin, Seraina Ruegger, Nils B. Weidmann, Lars-Erik
Cederman,and Kristian Skrede Gleditsch. 2022. "Mapping The International
System, 1886-2017: The CShapes 2.0 Dataset." Journal of Conflict
Resolution. 66(1): 144-161.
Weidmann, Nils B. and Kristian Skrede Gleditsch. 2010. "Mapping and Measuring
Country Shapes: The cshapes Package." The R Journal 2(1): 18-24