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. If hex=TRUE, the "hexademical" representation is returned as a character vector. If wkb=TRUE, the "well-known binary" representation is returned as a list of raw vectors.

Usage

## S4 method for signature 'SpatVector'
geom(x, wkt=FALSE, hex=FALSE, wkb=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
wkb	logical. If TRUE the raw WKB geometry is returned (unless either of hex or wkt is also TRUE)
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. 14, 2024, 5:07 p.m.