xor: Select parts of polygons not shared between two GVectors

In adamlilith/fasterRaster: Faster Raster and Spatial Vector Processing Using 'GRASS GIS'

Select parts of polygons not shared between two GVectors

Description

The xor() function selects the area that does not overlap between two "polygon" GVectors. You can also use the / operator, as in vect1 / vect2.

Usage

## S4 method for signature 'GVector,GVector'
xor(x, y)

Arguments

x, y

GVectors.

Value

A GVector.

See Also

crop(), intersect(), union(), erase()

Examples

if (grassStarted()) {

# Setup
library(sf)

# Polygon of coastal Madagascar and Dypsis specimens
madCoast4 <- fastData("madCoast4") # polygons
madDypsis <- fastData("madDypsis") # points

# Convert vectors:
coast4 <- fast(madCoast4)
dypsis <- fast(madDypsis)

# Create another polygons vector from a convex hull around Dypsis points
hull <- convHull(dypsis)

### union()
###########

unioned <- union(coast4, hull)
plot(unioned)

plus <- coast4 + hull # same as union()

### intersect
#############

inter <- intersect(coast4, hull)
plot(coast4)
plot(hull, border = "red", add = TRUE)
plot(inter, border = "blue", add = TRUE)

### xor
#######

xr <- xor(coast4, hull)
plot(coast4)
plot(xr, border = "blue", add = TRUE)

### erase
#########

erased <- erase(coast4, hull)
plot(coast4)
plot(erased, border = "blue", add = TRUE)

minus <- coast4 - hull # same as erase()

}

adamlilith/fasterRaster documentation built on Oct. 26, 2024, 4:06 p.m.