fsr (version 1.0.0)

spa_core: Capturing the core of a pgeometry object

Description

This function yields a crisp spatial object (as an sfg object) that corresponds to the core of a pgeometry object given as input.

Usage

spa_core(pgo)

Arguments

pgo

A pgeometry object of any type.

Value

An sfg object that represents the core of pgo. It can be an empty object if pgo does not have a component with membership degree 1.

Details

It employs the classical definition of core from the fuzzy set theory in the context of spatial plateau algebra. The core only comprises the points with membership degree equal to 1. Hence, this operation returns the sfg object that represents the component labeled with membership degree equal to 1 of the pgeometry object given as input. If the pgeometry object has no core, then an empty sfg object is returned (i.e., a crisp spatial object without points).

References

Carniel, A. C.; Schneider, M. A Conceptual Model of Fuzzy Topological Relationships for Fuzzy Regions. In Proceedings of the 2016 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE 2016), pp. 2271-2278, 2016.

Examples

# NOT RUN {
library(sf)

pts1 <- rbind(c(1, 2), c(3, 2))
pts2 <- rbind(c(1, 1), c(2, 3), c(2, 1))
pts3 <- rbind(c(2, 2), c(3, 3))

cp1 <- component_from_sfg(st_multipoint(pts1), 0.3)
cp2 <- component_from_sfg(st_multipoint(pts2), 0.6)
cp3 <- component_from_sfg(st_multipoint(pts3), 1.0)

pp <- create_pgeometry(list(cp1, cp2, cp3), "PLATEAUPOINT")
pp

pp_core <- spa_core(pp)
pp_core

#Creating a pgeometry object without core
pp2 <- create_pgeometry(list(cp1, cp2), "PLATEAUPOINT")
pp2

spa_core(pp2)

# }