fsr (version 1.0.0)

spa_boundary_pregion: Capturing the fuzzy boundary of a plateau region object

Description

This function yields a specific part of the fuzzy boundary of a plateau region object.

Usage

spa_boundary_pregion(pregion, bound_part = "region")

Arguments

pregion

A pgeometry object of the type PLATEAUREGION. It throws an error if a different type is given.

bound_part

A character value that indicates the part of the fuzzy boundary to be returned. It can be "region" or "line". See below for more details.

Value

A pgeometry object that represents a specific part of the fuzzy boundary of pgeometry object given as input.

Details

It employs the definition of fuzzy boundary of a fuzzy region object in the context of spatial plateau algebra (as defined in the references). The fuzzy boundary of a fuzzy region object A has a heterogeneous nature since it consists of two parts:

• a fuzzy line object that corresponds to the boundary of the core of A.

• a fuzzy region object that comprises all points of A with a membership degree greater than 0 and less than 1.

This means that the function spa_boundary_pregion can yield one specific part of the fuzzy boundary of a plateau region object (the argument pgeometry). If boundary = "line", then the function returns the boundary plateau line of pgeometry (i.e., returns a pgeometry object of the type PLATEAULINE). Else if boundary = "region" (the default value), then the function returns the boundary plateau region of pgeometry (i.e., returns a pgeometry object of the type PLATEAUREGION).

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.

• Carniel, A. C.; Schneider, M. Spatial Plateau Algebra: An Executable Type System for Fuzzy Spatial Data Types. In Proceedings of the 2018 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE 2018), pp. 1-8, 2018.

Examples

# NOT RUN {
library(tibble)
library(FuzzyR)

set.seed(123)

# some random points to create pgeometry objects by using the function spa_creator
tbl = tibble(x = runif(10, min= 0, max = 30), 
             y = runif(10, min = 0, max = 50), 
             z = runif(10, min = 0, max = 100))

classes <- c("category-1", "category-2")
mf1 <- genmf("trapmf", c(0, 5, 20, 35))
mf2 <- genmf("trimf", c(20, 80, 100))

pregions <- spa_creator(tbl, classes = classes, mfs = c(mf1, mf2))
pregions$pgeometry[[1]]
pregions$pgeometry[[2]]

# capturing and showing the boundary plateau line of each pgeometry object previously created
(spa_boundary_pregion(pregions$pgeometry[[1]], bound_part = "line")) 
(spa_boundary_pregion(pregions$pgeometry[[2]], bound_part = "line"))
# the last boundary is empty because there is no core! 

# capturing and showing the boundary plateau region (this is the default behavior)
(spa_boundary_pregion(pregions$pgeometry[[1]]))
(spa_boundary_pregion(pregions$pgeometry[[2]]))

# }