Make a spatial segment object

Make a spatial segment object

Usage

fm_segm(...)

# Default S3 method
fm_segm(loc = NULL, idx = NULL, grp = NULL, is.bnd = TRUE, crs = NULL, ...)

# S3 method for class 'fm_segm'
fm_segm(..., grp = NULL, grp.default = 0L, is.bnd = NULL)

# S3 method for class 'fm_segm_list'
fm_segm(x, grp = NULL, grp.default = 0L, ...)

fm_segm_join(x, grp = NULL, grp.default = 0L, is.bnd = NULL)

fm_segm_split(x, grp = NULL, grp.default = 0L)

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

# S3 method for class 'fm_mesh_2d'
fm_segm(x, boundary = TRUE, grp = NULL, ...)

fm_is_bnd(x)

fm_is_bnd(x) <- value

Arguments

...

Passed on to submethods

loc

Matrix of point locations, or SpatialPoints, or sf/sfc point object.

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 fm_rcdt_2d(). If is.bnd==TRUE, defaults to linking all the points in loc, as c(1:nrow(loc),1L), otherwise 1:nrow(loc).

grp

When joining segments, use these group labels for segments instead of the original group labels.

is.bnd

TRUE if the segments are boundary segments, otherwise FALSE.

crs

An optional fm_crs(), sf::st_crs() or sp::CRS() object

grp.default

If grp.default is NULL, use these group labels for segments with NULL group.

x

Mesh to extract segments from

boundary

logical; if TRUE, extract the boundary segments, otherwise interior constrain segments.

value

logical

Value

An fm_segm or fm_segm_list object

Methods (by class)

• fm_segm(fm_segm): Join multiple fm_segm objects into a single fm_segm object. If is.bnd is non-NULL, it overrides the input segment information. Otherwise, it checks if the inputs are consistent.

• fm_segm(fm_segm_list): Join fm_segm objects from a fm_segm_list into a single fm_segm object. Equivalent to fm_segm_join(x)

• fm_segm(fm_mesh_2d): Extract the boundary or interior segments of a 2d mesh. If grp is non-NULL, extracts only segments matching the matching the set of groups given by grp.

Functions

• fm_segm(): Create a new fm_segm object.

• fm_segm_join(): Join multiple fm_segm objects into a single fm_segm object. If is.bnd is non-NULL, it overrides the segment information. Otherwise it checks for consistency.

• fm_segm_split(): Split an fm_segm object by grp into an fm_segm_list object, optionally keeping only some groups.

See also

Other object creation and conversion: fm_as_fm(), fm_as_lattice_2d(), fm_as_mesh_1d(), fm_as_mesh_2d(), fm_as_segm(), fm_as_sfc(), fm_as_tensor(), fm_lattice_2d(), fm_mesh_1d(), fm_mesh_2d(), fm_simplify(), fm_tensor()

Examples

fm_segm(rbind(c(0, 0), c(1, 0), c(1, 1), c(0, 1)), is.bnd = FALSE)
#> fm_segm object:
#>   3 interior edges
#>   Bounding box = (0,1) x (0,1) x (0,0)
fm_segm(rbind(c(0, 0), c(1, 0), c(1, 1), c(0, 1)), is.bnd = TRUE)
#> fm_segm object:
#>   4 boundary edges
#>   Bounding box = (0,1) x (0,1) x (0,0)

fm_segm_join(fmexample$boundary_fm)
#> fm_segm object:
#>   72 boundary edges (1 group: 1)
#>   Bounding box = (-5.331027, 4.061656) x (-3.998161, 5.415609) x (0,0)

fm_segm(fmexample$mesh, boundary = TRUE)
#> fm_segm object:
#>   29 boundary edges (1 group: 1)
#>   Bounding box = (-5.331027, 4.061656) x (-3.998161, 5.415609) x (0,0)
fm_segm(fmexample$mesh, boundary = FALSE)
#> fm_segm object:
#>   54 interior edges (1 group: 1)
#>   Bounding box = (-3.344418, 2.076846) x (-1.995602, 3.404937) x (0,0)