Non-convex hull computation

Legacy method for INLA::inla.nonconvex.hull(). Use fm_nonconvex_hull() with method = "fm" instead, with either format = "fm" (for compatibility with code expecting fm_segm output) or format = "sf".

Usage

fm_nonconvex_hull_inla(
  x,
  convex = -0.15,
  concave = convex,
  resolution = 40,
  eps = NULL,
  eps_rel = NULL,
  crs = NULL,
  ...
)

fm_nonconvex_hull_inla_basic(
  x,
  convex = -0.15,
  resolution = 40,
  eps = NULL,
  crs = fm_crs(x)
)

Arguments

x: A spatial object
convex: numeric vector; How much to extend
concave: numeric vector; The minimum allowed reentrant curvature. Default equal to convex
resolution: integer; The internal computation resolution. A warning will be issued when this needs to be increased for higher accuracy, with the required resolution stated. For method="fm" only.
eps, eps_rel: The polygonal curve simplification tolerances used for simplifying the resulting boundary curve. See fm_simplify_helper() for details. For method="fm" only.
crs: Optional crs object for the resulting polygon. Default is fm_crs(x)
...: Unused.

Value

fm_nonconvex_hull_inla() returns an fm_segm object, for compatibility with inla.nonconvex.hull().

Functions

fm_nonconvex_hull_inla_basic(): Special method fm_nonconvex_hull_fm() method for concave = 0. Requires splancs::nndistF().

INLA compatibility

For mesh and curve creation, the fm_rcdt_2d_inla(), fm_mesh_2d_inla(), and fm_nonconvex_hull_inla() methods will keep the interface syntax used by INLA::inla.mesh.create(), INLA::inla.mesh.2d(), and INLA::inla.nonconvex.hull() functions, respectively, whereas the fm_rcdt_2d(), fm_mesh_2d(), and fm_nonconvex_hull() interfaces may be different, and potentially change in the future.

Examples

# New preferred method for "fm_segm" output:
fm_nonconvex_hull(cbind(0, 0), convex = 1, format = "fm")
#> fm_segm object:
#>   32 boundary edges (1 group: 1)
#>   Bounding box = (-0.9992483, 0.9992483) x (-0.9992483, 0.9992483) x (0,0)

# Deprecated:
suppressWarnings(
  fm_nonconvex_hull_inla(cbind(0, 0), convex = 1)
)
#> fm_segm object:
#>   32 boundary edges (1 group: 1)
#>   Bounding box = (-0.9992483, 0.9992483) x (-0.9992483, 0.9992483) x (0,0)