tileindex: Determine Which Tile Contains Each Given Point

In spatstat.geom: Geometrical Functionality of the 'spatstat' Family

Determine Which Tile Contains Each Given Point

Description

Given a tessellation and a list of spatial points, determine which tile of the tessellation contains each of the given points.

Usage

tileindex(x, y, Z, close.gaps=TRUE, all.inside=FALSE)

Arguments

x, y	Spatial coordinates. Numeric vectors of equal length. (Alternatively y may be missing and x may be an object containing spatial coordinates).
Z	A tessellation (object of class "tess").
close.gaps	Logical value specifying whether all points x,y lying inside the window of Z must be classified as belonging to a tile. This avoids the effect of numerical errors in the tile geometry. See Details.
all.inside	Logical value specifying whether all points x,y should be classified as lying inside a tile. This implies that points lying outside the window will be assigned to the closest tile. See Details.

Details

This function determines which tile of the tessellation Z contains each of the spatial points with coordinates (x[i],y[i]).

The result is a factor, of the same length as x and y, indicating which tile contains each point. The levels of the factor are the names of the tiles of Z.

A point lying outside the window containing the tessellation is assigned the value NA by default. However if all.inside=TRUE is specified, then every point will be assigned to the closest tile, and no NA values are returned.

It is possible that, due to numerical error, a point lying inside the window may not be classified as belonging to any of the tiles of Z. If this occurs, the default behaviour is to assign the point to the closest tile. This can be suppressed by setting close.gaps=FALSE (and all.inside=FALSE); in that case, NA values are returned for such points.

Value

A factor, of the same length as x and y, whose levels are the names of the tiles of Z. The factor values may include NA unless all.inside=TRUE was specified.

Author(s)

\spatstatAuthors

See Also

cut.ppp and split.ppp to divide up the points of a point pattern according to a tessellation.

as.function.tess to create a function whose value is the tile index.

Examples

  X <- runifrect(7)
  V <- dirichlet(X)
  tileindex(0.1, 0.4, V)
  tileindex(list(x=0.1, y=0.4), Z=V)
  tileindex(X, Z=V)

spatstat.geom documentation built on Jan. 20, 2026, 5:08 p.m.