geometry: Get the geometry (coordinates) of a SpatVector

In terra: Spatial Data Analysis

Get the geometry (coordinates) of a SpatVector

Description

Get the geometry of a SpatVector. If wkt=FALSE, this is a five-column matrix or data.frame: the vector object ID, the IDs for the parts of each object (e.g. five polygons that together are one spatial object), the x (longitude) and y (latitude) coordinates, and a flag indicating whether the part is a "hole" (only relevant for polygons).

If wkt=TRUE, the "well-known text" representation is returned as a character vector.

Usage

## S4 method for signature 'SpatVector'
geom(x, wkt=FALSE, hex=FALSE, df=FALSE, list=FALSE, xnm="x", ynm="y")

Arguments

x	SpatVector
wkt	logical. If TRUE the WKT geometry is returned (unless hex is also TRUE)
hex	logical. If TRUE the hexadecimal geometry is returned
df	logical. If TRUE a data.frame is returned instead of a matrix (only if wkt=FALSE, hex=FALSE, and list=FALSE)
list	logical. If TRUE a nested list is returned with data.frames of coordinates
xnm	character. If list=TRUE the "x" column name for the coordinates data.frame
ynm	character. If list=TRUE the "y" column name for the coordinates data.frame

Value

matrix, vector, data.frame, or list

See Also

crds, xyFromCell

Examples

x1 <- rbind(c(-175,-20), c(-140,55), c(10, 0), c(-140,-60))
x2 <- rbind(c(-125,0), c(0,60), c(40,5), c(15,-45))
x3 <- rbind(c(-10,0), c(140,60), c(160,0), c(140,-55))
x4 <- rbind(c(80,0), c(105,13), c(120,2), c(105,-13))
z <- rbind(cbind(object=1, part=1, x1), cbind(object=2, part=1, x2), 
           cbind(object=3, part=1, x3), cbind(object=3, part=2,  x4))
colnames(z)[3:4] <- c('x', 'y')
z <- cbind(z, hole=0)
z[(z[, "object"]==3 & z[,"part"]==2), "hole"] <- 1

p <- vect(z, "polygons")
geom(p)

f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
g <- geom(v)
head(g)

w <- geom(v, wkt=TRUE)
substr(w, 1, 60)

terra documentation built on Oct. 13, 2023, 5:08 p.m.