R: Extract or Change Coordinates of a Spatial or Spatiotemporal...

coords {spatstat} | R Documentation

## Extract or Change Coordinates of a Spatial or Spatiotemporal Point Pattern

### Description

Given any kind of spatial or space-time point pattern, this function extracts the (space and/or time and/or local) coordinates of the points and returns them as a data frame.

### Usage

      coords(x, ...)
      ## S3 method for class 'ppp'
    coords(x, ...)
      ## S3 method for class 'ppx'
    coords(x, ..., spatial = TRUE, temporal = TRUE, local=TRUE)
      coords(x, ...) <- value
      ## S3 replacement method for class 'ppp'
    coords(x, ...) <- value
      ## S3 replacement method for class 'ppx'
    coords(x, ..., spatial = TRUE, temporal = TRUE, local=TRUE) <- value

### Arguments

`x` | A point pattern: either a two-dimensional point pattern (object of class `"ppp"`), a three-dimensional point pattern (object of class `"pp3"`), or a general multidimensional space-time point pattern (object of class `"ppx"`).
`...` | Further arguments passed to methods.
`spatial,temporal,local` | Logical values indicating whether to extract spatial, temporal and local coordinates, respectively. The default is to return all such coordinates. (Only relevant to `ppx` objects).
`value` | New values of the coordinates. A numeric vector with one entry for each point in `x`, or a numeric matrix or data frame with one row for each point in `x`.

### Details

The function `coords` extracts the coordinates from a point pattern. The function `coords<-` replaces the coordinates of the point pattern with new values.

Both functions `coords` and `coords<-` are generic, with methods for the classes `"ppp"`) and `"ppx"`. An object of class `"pp3"` also inherits from `"ppx"` and is handled by the method for `"ppx"`.

### Value

`coords` returns a `data.frame` with one row for each point, containing the coordinates. `coords<-` returns the altered point pattern.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

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

### See Also

`ppx`, `pp3`, `ppp`, `as.hyperframe.ppx`, `as.data.frame.ppx`.

### Examples

       df <- data.frame(x=runif(4),y=runif(4),t=runif(4))
       X <- ppx(data=df, coord.type=c("s","s","t"))
       coords(X)
       coords(X, temporal=FALSE)
       coords(X) <- matrix(runif(12), ncol=3)

[Package spatstat version 1.54-0 Index]