sf (version 0.1)

sf: create sf object

Description

create sf, which extends data.frame-like objects with a simple feature list column

Usage

sf(df, relation_to_geometry = rep(as.character(NA), ncol(df) - 1))

Arguments

df

object of class data.frame

relation_to_geometry

character vector; indicates for each attribute column how it relates to the geometry; see Details

Details

relation_to_geometry specified for each attribute column how it relates to the geometry, and can have one of following values: "field", "lattice", "entity". "field" is used for attributes that are constant throughout the geometry (e.g. land use), "lattice" where the attribute is an aggregate value over the geometry (e.g. population density), "entity" when the attributes identifies the geometry of particular "thing", such as a building or a city.

Examples

pt1 = POINT(c(0,1))
pt2 = POINT(c(1,1))
sfc(list(pt1, pt2))
d = data.frame(a = 1:2)
d$geom = sfc(list(pt1, pt2))
df = sf(d)
d$geom2 = sfc(list(pt1, pt2))
sf(df) # warns