fm_rcdt_2d: Refined Constrained Delaunay Triangulation

In fmesher: Triangle Meshes and Related Geometry Tools

Refined Constrained Delaunay Triangulation

Description

Computes a refined constrained Delaunay triangulation on R2 or S2.

Usage

fm_rcdt_2d(...)

fm_rcdt_2d_inla(
  loc = NULL,
  tv = NULL,
  boundary = NULL,
  interior = NULL,
  extend = (missing(tv) || is.null(tv)),
  refine = FALSE,
  lattice = NULL,
  globe = NULL,
  cutoff = 1e-12,
  quality.spec = NULL,
  crs = NULL,
  ...
)

fm_delaunay_2d(loc, crs = NULL, ...)

Arguments

...	Currently passed on to fm_mesh_2d_inla or converted to fmesher_rcdt() options.
loc	Input coordinates that should be part of the mesh. Can be a matrix, sf, sfc, SpatialPoints, or other object supported by fm_unify_coords().
tv	Initial triangulation, as a N-by-3 index vector into loc
boundary, interior	Objects supported by fm_as_segm(). If boundary is numeric, fm_nonconvex_hull(loc, convex = boundary) is used.
extend	logical or list specifying whether to extend the data region, with parameters list("n") the number of edges in the extended boundary (default=16) list("offset") the extension distance. If negative, interpreted as a factor relative to the approximate data diameter (default=-0.10) Setting to FALSE is only useful in combination lattice or boundary.
refine	logical or list specifying whether to refine the triangulation, with parameters list("min.angle") the minimum allowed interior angle in any triangle. The algorithm is guaranteed to converge for min.angle at most 21 (default=21) list("max.edge") the maximum allowed edge length in any triangle. If negative, interpreted as a relative factor in an ad hoc formula depending on the data density (default=Inf) list("max.n.strict") the maximum number of vertices allowed, overriding min.angle and max.edge (default=-1, meaning no limit) list("max.n") the maximum number of vertices allowed, overriding max.edge only (default=-1, meaning no limit)
lattice	An fm_lattice_2d object, generated by fm_lattice_2d(), specifying points on a regular lattice.
globe	If non-NULL, an integer specifying the level of subdivision for global mesh points, used with fmesher_globe_points()
cutoff	The minimum allowed distance between points. Point at most as far apart as this are replaced by a single vertex prior to the mesh refinement step.
quality.spec	List of vectors of per vertex max.edge target specification for each location in loc, boundary/interior (segm), and lattice. Only used if refining the mesh.
crs	Optional crs object

Value

An fm_mesh_2d object

Functions

• fm_rcdt_2d_inla(): Legacy method for the INLA::inla.mesh.create() interface

• fm_delaunay_2d(): Construct a plain Delaunay triangulation.

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

(m <- fm_rcdt_2d_inla(
  boundary = fm_nonconvex_hull(cbind(0, 0), convex = 5)
))

fm_delaunay_2d(matrix(rnorm(30), 15, 2))

fmesher documentation built on July 1, 2024, 5:07 p.m.