inla.mesh.segment {INLA}

R Documentation

Constraint segments for inla.mesh

Description

Constructs inla.mesh.segment objects that can be used to specify boundary and interior constraint edges in calls to inla.mesh().

Usage

inla.mesh.segment(...)

## Default S3 method:
inla.mesh.segment(
  loc = NULL,
  idx = NULL,
  grp = NULL,
  is.bnd = TRUE,
  crs = NULL,
  ...
)

## S3 method for class 'inla.mesh.segment'
inla.mesh.segment(..., grp.default = 0)

inla.contour.segment(
  x = seq(0, 1, length.out = nrow(z)),
  y = seq(0, 1, length.out = ncol(z)),
  z,
  nlevels = 10,
  levels = pretty(range(z, na.rm = TRUE), nlevels),
  groups = seq_len(length(levels)),
  positive = TRUE,
  eps = NULL,
  crs = NULL
)

Arguments

...	Additional parameters. When joining segments, a list of inla.mesh.segment objects.
loc	Matrix of point locations.
idx	Segment index sequence vector or index pair matrix. The indices refer to the rows of loc. If loc==NULL, the indices will be interpreted as indices into the point specification supplied to inla.mesh.create(). If is.bnd==TRUE, defaults to linking all the points in loc, as c(1:nrow(loc),1L), otherwise 1:nrow(loc).
grp	Vector of group labels for each segment. Set to NULL to let the labels be chosen automatically in a call to inla.mesh.create().
is.bnd	TRUE if the segments are boundary segments, otherwise FALSE.
crs	An optional CRS or inla.CRS object
grp.default	When joining segments, use this group label for segments that have grp=NULL.
x, y, z, nlevels, levels	Parameters specifying a set of surface contours, with syntax described in contour().
groups	Vector of group ID:s, one for each contour level.
positive	TRUE if the contours should encircle positive level excursions in a counter clockwise direction.
eps	Tolerance for inla.simplify.curve().

Value

An inla.mesh.segment object.

Author(s)

Finn Lindgren finn.lindgren@gmail.com

See Also

inla.mesh.create(), inla.mesh.2d()

Examples

## Create a square boundary and a diagonal interior segment
loc.bnd <- matrix(c(0, 0, 1, 0, 1, 1, 0, 1), 4, 2, byrow = TRUE)
loc.int <- matrix(c(0.9, 0.1, 0.1, 0.6), 2, 2, byrow = TRUE)
segm.bnd <- inla.mesh.segment(loc.bnd)
segm.int <- inla.mesh.segment(loc.int, is.bnd = FALSE)

## Points to be meshed
loc <- matrix(runif(10 * 2), 10, 2) * 0.9 + 0.05
mesh <- inla.mesh.create(loc,
    boundary = segm.bnd,
    interior = segm.int,
    refine = list()
)
plot(mesh)
## Not run: 
mesh <- inla.mesh.create(loc, interior = list(segm.bnd, segm.int))
plot(mesh)

## End(Not run)

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