Spatial relations

The following makes use of the sf package. You may need to install it from CRAN using the code install.packages("sf") if you want to run this on your computer. (The package is already installed on the notebook container, however.)

library(sf)

Linking to GEOS 3.9.0, GDAL 3.2.2, PROJ 7.2.1; sf_use_s2() is TRUE

The file "south-america-1990.RData" loaded below was created in a previous example was created in a previous example.

load("south-america-1990.RData")

plot_g <- function(x,...) plot(st_geometry(x),...)
plot_g(Brazil)
plot_g(Brasilia,add=TRUE,pch=19) # Circle
plot_g(Bogota,add=TRUE,pch=15) # Square
spatial-relations_5_0.png 
st_contains(Brazil,Brasilia,sparse=FALSE)

     [,1]
[1,] TRUE

st_contains(Brazil,Bogota,sparse=FALSE)

      [,1]
[1,] FALSE

load("cshapes-1990.RData")
ThreeCountries <-
    subset(cshapes.1990,
           CNTRY_NAME %in% c("Brazil","Chile","Colombia"))
rownames(ThreeCountries) <- ThreeCountries$CNTRY_NAME

ThreeCapitals <-
    subset(cshapes.capitals.1990,
           CNTRY_NAME %in% c("Brazil","Chile","Colombia"))
rownames(ThreeCapitals) <- ThreeCapitals$CAPNAME

plot_g(ThreeCountries)
plot_g(ThreeCapitals,add=TRUE,pch=19)
spatial-relations_10_0.png 
st_contains(ThreeCountries,ThreeCapitals,sparse=FALSE)

      [,1]  [,2]  [,3]
[1,]  TRUE FALSE FALSE
[2,] FALSE  TRUE FALSE
[3,] FALSE FALSE  TRUE

structure(
   st_contains(ThreeCountries,ThreeCapitals,sparse=FALSE),
   dimnames=list(rownames(ThreeCountries),rownames(ThreeCapitals))
)

         Brasilia Santiago Bogota
Brazil       TRUE    FALSE  FALSE
Chile       FALSE     TRUE  FALSE
Colombia    FALSE    FALSE   TRUE

st_touches(Brazil,Colombia,sparse=FALSE)

     [,1]
[1,] TRUE

st_touches(Brazil,Chile,sparse=FALSE)

      [,1]
[1,] FALSE

structure(
   st_touches(ThreeCountries,sparse=FALSE),
   dimnames=list(rownames(ThreeCountries),rownames(ThreeCountries))
)

         Brazil Chile Colombia
Brazil    FALSE FALSE     TRUE
Chile     FALSE FALSE    FALSE
Colombia   TRUE FALSE    FALSE

save(ThreeCountries,ThreeCapitals,file="three-countries.RData")