Add minimum distance data to your data frame
Source:R/add_minimum_distance.R
add_minimum_distance.Rdadd_minimum_distance() allows you to add the minimum
distance (in kilometers) to a (dyad-year, leader-year, leader-dyad-year, state-year) data frame. These estimates
are recorded in the cow_mindist and gw_mindist data that come with this package. The
data are current as of the end of 2019.
Value
add_minimum_distance() takes a (dyad-year, leader-year, leader-dyad-year, state-year) data frame and adds the
minimum distance between the first state and the second state (in dyad-year data) or the minimum
minimum (sic) distance for a given state in a given year.
Details
The function leans on attributes of the data that are provided by one of the "create" functions
in this package (e.g. create_dyadyear() or create_stateyear()).
References
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.
Examples
# \donttest{
# just call `library(tidyverse)` at the top of the your script
library(magrittr)
cow_ddy %>% add_minimum_distance()
#> Joining with `by = join_by(ccode1, ccode2, year)`
#> # A tibble: 2,139,270 × 4
#> ccode1 ccode2 year mindist
#> <dbl> <dbl> <dbl> <dbl>
#> 1 2 20 1920 NA
#> 2 2 20 1921 0
#> 3 2 20 1922 0
#> 4 2 20 1923 0
#> 5 2 20 1924 0
#> 6 2 20 1925 0
#> 7 2 20 1926 0
#> 8 2 20 1927 0
#> 9 2 20 1928 0
#> 10 2 20 1929 0
#> # ℹ 2,139,260 more rows
create_dyadyears(system = "gw") %>% add_minimum_distance()
#> Joining with `by = join_by(gwcode1, gwcode2, year)`
#> Joining with `by = join_by(gwcode1, gwcode2, year)`
#> # A tibble: 2,089,826 × 4
#> gwcode1 gwcode2 year mindist
#> <dbl> <dbl> <dbl> <dbl>
#> 1 2 20 1867 NA
#> 2 2 20 1868 NA
#> 3 2 20 1869 NA
#> 4 2 20 1870 NA
#> 5 2 20 1871 NA
#> 6 2 20 1872 NA
#> 7 2 20 1873 NA
#> 8 2 20 1874 NA
#> 9 2 20 1875 NA
#> 10 2 20 1876 NA
#> # ℹ 2,089,816 more rows
create_stateyears(system ="gw") %>% add_minimum_distance()
#> Joining with `by = join_by(gwcode, year)`
#> # A tibble: 18,637 × 4
#> gwcode statename year minmindist
#> <dbl> <chr> <dbl> <dbl>
#> 1 2 United States of America 1816 NA
#> 2 2 United States of America 1817 NA
#> 3 2 United States of America 1818 NA
#> 4 2 United States of America 1819 NA
#> 5 2 United States of America 1820 NA
#> 6 2 United States of America 1821 NA
#> 7 2 United States of America 1822 NA
#> 8 2 United States of America 1823 NA
#> 9 2 United States of America 1824 NA
#> 10 2 United States of America 1825 NA
#> # ℹ 18,627 more rows
# }