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Spatial Operations on Shapefiles

Source: R/utils_shapefile.R
shapefile_operations.Rd

These functions perform various spatial operations on two shapefiles, including determining which geometries fall within, outside, touch, cross, overlap, or intersect another geometry. They also include functions for geometric operations such as intersection, difference, and union.

Usage

shapefile_within(shp1, shp2)

shapefile_outside(shp1, shp2)

shapefile_overlaps(shp1, shp2)

shapefile_touches(shp1, shp2)

shapefile_crosses(shp1, shp2)

shapefile_intersection(shp1, shp2)

shapefile_difference(shp1, shp2)

shapefile_union(shp1, shp2)

Arguments

shp1

An sf object representing the first shapefile.

shp2

An sf object representing the second shapefile.

Value

A filtered sf object or the result of the geometric operation.

Details

All functions ensure that the coordinate reference systems (CRS) of both shapefiles are the same before performing operations. If the CRSs are different, shp2 will be transformed to match the CRS of shp1.

  • shapefile_within(): Filters features in shp1 that are fully within shp2.

  • shapefile_outside(): Filters features in shp1 that are outside or do not overlap shp2.

  • shapefile_overlaps(): Filters features in shp1 that overlap with shp2.

  • shapefile_touches(): Filters features in shp1 that touch the boundary of shp2.

  • shapefile_crosses(): Filters features in shp1 that cross through shp2.

  • shapefile_intersection(): Computes the geometric intersection of shp1 and shp2.

  • shapefile_difference(): Computes the geometric difference of shp1 minus shp2.

  • shapefile_union(): Computes the geometric union of shp1 and shp2.

Examples

if (interactive() && requireNamespace("EBImage")) {
library(pliman)

shp1 <- shapefile_input(paste0(image_pliman(), "/shp1.rds"))
shp2 <- shapefile_input(paste0(image_pliman(), "/shp2.rds"))
shapefile_view(shp1) + shapefile_view(shp1)

# Apply operations
shapefile_within(shp1, shp2)
shapefile_outside(shp1, shp2)
shapefile_overlaps(shp1, shp2)
shapefile_touches(shp1, shp2)
shapefile_crosses(shp1, shp2)
shapefile_intersection(shp1, shp2)
shapefile_difference(shp1, shp2)
shapefile_union(shp1, shp2)
}