spatstat (version 1.64-1)

hextess: Hexagonal Grid or Tessellation

Description

Construct a hexagonal grid of points, or a hexagonal tessellation.

Usage

hexgrid(W, s, offset = c(0, 0), origin=NULL, trim = TRUE)
hextess(W, s, offset = c(0, 0), origin=NULL, trim = TRUE)

Arguments

W

Window in which to construct the hexagonal grid or tessellation. An object of class "owin".

s

Side length of hexagons. A positive number.

offset

Numeric vector of length 2 specifying a shift of the hexagonal grid. See Details.

origin

Numeric vector of length 2 specifying the initial origin of the hexagonal grid, before the offset is applied. See Details.

trim

Logical value indicating whether to restrict the result to the window W. See Details.

Value

The value of hexgrid is a point pattern (object of class "ppp").

The value of hextess is a tessellation (object of class "tess").

Details

hexgrid constructs a hexagonal grid of points on the window W. If trim=TRUE (the default), the grid is intersected with W so that all points lie inside W. If trim=FALSE, then we retain all grid points which are the centres of hexagons that intersect W.

hextess constructs a tessellation of hexagons on the window W. If trim=TRUE (the default), the tessellation is restricted to the interior of W, so that there will be some fragmentary hexagons near the boundary of W. If trim=FALSE, the tessellation consists of all hexagons which intersect W.

The points of hexgrid(...) are the centres of the tiles of hextess(...) in the same order.

In the initial position of the grid or tessellation, one of the grid points (tile centres) is placed at the origin, which defaults to the midpoint of the bounding rectangle of W. The grid can be shifted relative to this origin by specifing the offset.

See Also

tess

hexagon

Examples

# NOT RUN {
  if(interactive()) {
    W <- Window(chorley)
    s <- 0.7
  } else {
    W <- letterR
    s <- 0.3
  }
  plot(hextess(W, s))
  plot(hexgrid(W, s), add=TRUE)
# }