R: Intersection of Two Tessellations

intersect.tess {spatstat} | R Documentation

## Intersection of Two Tessellations

### Description

Yields the intersection of two tessellations, or the intersection of a tessellation with a window.

### Usage

       intersect.tess(X, Y, ..., keepmarks=FALSE, sep="x")

### Arguments

`X,Y` | Two tessellations (objects of class `"tess"`), or windows (objects of class `"tess"`), or other data that can be converted to tessellations by `as.tess`.
`...` | Optional arguments passed to `as.mask` to control the discretisation, if required.
`keepmarks` | Logical value. If `TRUE`, the marks attached to the tiles of `X` and `Y` will be retained as marks of the intersection tiles.
`sep` | Character string used to separate the names of tiles from `X` and from `Y`, when forming the name of the tiles of the intersection.

### Details

A tessellation is a collection of disjoint spatial regions (called tiles) that fit together to form a larger spatial region. See `tess`.

If `X` and `Y` are not tessellations, they are first converted into tessellations by `as.tess`.

The function `intersect.tess` then computes the intersection between the two tessellations. This is another tessellation, each of whose tiles is the intersection of a tile from `X` and a tile from `Y`.

One possible use of this function is to slice a window `W` into subwindows determined by a tessellation. See the Examples.

### Value

A tessellation (object of class `"tess"`).

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### See Also

`tess`, `as.tess`, `intersect.owin`

### Examples

      opa <- par(mfrow=c(1,3))
    # polygon
      data(letterR)
      plot(letterR)
    # tessellation of rectangles
      X <- tess(xgrid=seq(2, 4, length=10), ygrid=seq(0, 3.5, length=8))
      plot(X)
      plot(intersect.tess(X, letterR))

      A <- runifpoint(10)
      B <- runifpoint(10)
      plot(DA <- dirichlet(A))
      plot(DB <- dirichlet(B))
      plot(intersect.tess(DA, DB))
      par(opa)

      marks(DA) <- 1:10
      marks(DB) <- 1:10
      plot(Z <- intersect.tess(DA,DB, keepmarks=TRUE))
      mZ <- marks(Z)
      tZ <- tiles(Z)
      for(i in which(mZ[,1] == 3)) plot(tZ[[i]], add=TRUE, col="pink")

[Package spatstat version 1.63-3 Index]