terra (version 0.9-11)

vect: Create SpatVector objects

Description

Create a new SpatVector

Usage

# S4 method for character
vect(x, ...)
# S4 method for data.frame
vect(x, type="points", atts=NULL, crs=NA, ...)
# S4 method for sf
vect(x, ...)

Arguments

x

character (filename or "Well Known Text"), data.frame, matrix, missing, or a vector object defined in packages sf or sp

type

character. Geometry type. Must be "points", "lines", or "polygons"

atts

data.frame with the attributes. The number of rows must match the number of geometrical elements

crs

the coordinate reference system (PROJ4 notation)

...

additional matrices and/or lists with matrices

Value

SpatVector

See Also

geom

Examples

# NOT RUN {
f <- system.file("ex/lux.shp", package="terra")
f
v <- vect(f)
v

x1 <- rbind(c(-180,-20), c(-140,55), c(10, 0), c(-140,-60))
x2 <- rbind(c(-10,0), c(140,60), c(160,0), c(140,-55))
x3 <- rbind(c(-125,0), c(0,60), c(40,5), c(15,-45))
hole <- rbind(c(80,0), c(105,13), c(120,2), c(105,-13))

z <- rbind(cbind(object=1, part=1, x1, hole=0), cbind(object=2, part=1, x3, hole=0),
			cbind(object=3, part=1, x2, hole=0), cbind(object=3, part=1, hole, hole=1))
colnames(z)[3:4] <- c('x', 'y')
z <- data.frame(z)

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

z[z$hole==1, "object"] <- 4
lns <- vect(z[,1:4], "lines")
plot(p)
lines(lns, col='red')

w <- vect("POLYGON ((0 -5, 10 0, 10 -10, 0 -5))")

wkt <- c("MULTIPOLYGON ( ((40 40, 20 45, 45 30, 40 40)), 
((20 35, 10 30, 10 10, 30 5, 45 20, 20 35),(30 20, 20 15, 20 25, 30 20)))", 
"POLYGON ((0 -5, 10 0, 10 -10, 0 -5))")
w <- vect(wkt)

# }