Get the geometry (coordinates) of a SpatVector

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 class '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)
#>       geom part    x   y hole
#>  [1,]    1    1 -175 -20    0
#>  [2,]    1    1 -140  55    0
#>  [3,]    1    1   10   0    0
#>  [4,]    1    1 -140 -60    0
#>  [5,]    1    1 -175 -20    0
#>  [6,]    2    1 -125   0    0
#>  [7,]    2    1    0  60    0
#>  [8,]    2    1   40   5    0
#>  [9,]    2    1   15 -45    0
#> [10,]    2    1 -125   0    0
#> [11,]    3    1  -10   0    0
#> [12,]    3    1  140  60    0
#> [13,]    3    1  160   0    0
#> [14,]    3    1  140 -55    0
#> [15,]    3    1  -10   0    0
#> [16,]    3    1   80   0    1
#> [17,]    3    1  105  13    1
#> [18,]    3    1  120   2    1
#> [19,]    3    1  105 -13    1
#> [20,]    3    1   80   0    1

f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
g <- geom(v)
head(g)
#>      geom part        x        y hole
#> [1,]    1    1 6.026519 50.17767    0
#> [2,]    1    1 6.031361 50.16563    0
#> [3,]    1    1 6.035646 50.16410    0
#> [4,]    1    1 6.042747 50.16157    0
#> [5,]    1    1 6.043894 50.16116    0
#> [6,]    1    1 6.048243 50.16008    0

w <- geom(v, wkt=TRUE)
substr(w, 1, 60)
#>  [1] "POLYGON ((6.026519 50.17767, 6.031361 50.165627, 6.035646 50"
#>  [2] "POLYGON ((6.178368 49.876823, 6.185479 49.870525, 6.189417 4"
#>  [3] "POLYGON ((5.881378 49.870148, 5.881672 49.868866, 5.886637 4"
#>  [4] "POLYGON ((6.131309 49.972565, 6.134291 49.972382, 6.139316 4"
#>  [5] "POLYGON ((5.977929 50.026016, 5.982312 50.022949, 5.981743 5"
#>  [6] "POLYGON ((6.385532 49.837029, 6.3886 49.833683, 6.390184 49."
#>  [7] "POLYGON ((6.316665 49.623375, 6.31835 49.623157, 6.320131 49"
#>  [8] "POLYGON ((6.425158 49.731644, 6.42657 49.73082, 6.427332 49."
#>  [9] "POLYGON ((5.998312 49.699924, 5.998632 49.698559, 5.998956 4"
#> [10] "POLYGON ((6.039474 49.448261, 6.036906 49.448696, 6.036822 4"
#> [11] "POLYGON ((6.155963 49.685047, 6.159284 49.685036, 6.161457 4"
#> [12] "POLYGON ((6.067982 49.828465, 6.071922 49.825478, 6.073236 4"