New construction policy

[FelipeBrusse]

In this issue, I developed the inclusion of the Convex hull construction policy in the spa_creator function of the fsr package, according to the source code below and according to the paper A Systematic Approach to Creating Fuzzy Region Objects from Real Spatial Data Sets.

 convex_hull <- function(fsp, M, d){
  result_classes <- list(ncol(fsp) - 3)
  cls <- colnames(fsp)[-c(1:3)]
  for(k in 4:ncol(fsp)){  
    
    result_classes[[k-3]] <- create_empty_pgeometry("PLATEAUREGION")
    j <- 1
    for (i in M){
      res <- filter(fsp, fsp[,k] > 0 & (abs(fsp[,k] - i) <= d))
      
      j <- j+1
      pts <- st_as_sf(res, coords = c(1, 2))
      ch <- st_convex_hull(do.call(c, st_geometry(pts)))
      if(inherits(ch, c("POLYGON", "MULTIPOLYGON"))){
        comp <- component_from_sfg(ch, i)
        pregion <- create_pgeometry(list(comp), "PLATEAUREGION")
        result_classes[[k-3]] <- spa_union(result_classes[[k-3]], pregion)
      }
    }
    
    pgeoms <- tibble(class = cls, pgeometry = result_classes)
    
  }
   
    return(pgeoms)
  
}

The documentation needs to be produced and the function needs to be integrated into the spa_creator.

[accarniel]

Thank you for your contribution. The inclusion of this construction policy will make the spa_creator function compatible with the mentioned article. We have adapted this function and incorporated it into fsr.