2.3 Simple features (sf)

It is an open standard from Open Geospatial Consortium.

The standard has 18 geometry types and sf implement the 7 most import ones (points, lines, polygons, their multi-counterparts and geometry collection).

# TODO live
vignette(package = "sf")
vignette("sf1")

Simple features are stored in data frame with a special column (geom / geometry).

To explore it we will use the world data from spData(?world).

sf provides a method for the generic function plot:

plot(world)

## Warning: plotting the first 9 out of 10 attributes; use max.plot = 10 to plot
## all

It can be manipulated like any other data.frame.

summary(world["lifeExp"])

##     lifeExp                 geom    
##  Min.   :50.62   MULTIPOLYGON :177  
##  1st Qu.:64.96   epsg:4326    :  0  
##  Median :72.87   +proj=long...:  0  
##  Mean   :70.85                      
##  3rd Qu.:76.78                      
##  Max.   :83.59                      
##  NA's   :10

This object are easy to subset ([row, column]).