ppx: Multidimensional Space-Time Point Pattern

Description

Creates a multidimensional space-time point pattern with any kind of coordinates and marks.

Usage

ppx(data, domain=NULL, spatial = NULL, temporal = NULL)

Arguments

data

The coordinates and marks of the points. A data.frame or hyperframe.

domain

Optional. The space-time domain containing the points. An object in some appropriate format, or NULL.

spatial

Character vector giving the names of the columns of data that should be interpreted as spatial coordinates.

temporal

Character vector giving the names of the columns of data that should be interpreted as temporal coordinates.

Value

An object of class "ppx".

Details

An object of class "ppx" represents a marked point pattern in multidimensional space and/or time. There may be any number of spatial coordinates, any number of temporal coordinates, and any number of mark variables. The individual marks may be atomic (numeric values, factor values, etc) or objects of any kind.

The argument data should contain the coordinates and marks of the points. It should be a data.frame or more generally a hyperframe (see hyperframe) with one row of data for each point.

Each column of data is either a spatial coordinate, a temporal coordinate, or a mark variable. The argument spatial determines which columns are interpreted as spatial coordinates: if it is present, spatial should be a character vector matching the names of columns of data. Similarly the argument temporal determines which columns are interpreted as temporal coordinates. By default, columns of numerical data are assumed to represent spatial coordinates.

Examples

Run this code

df <- data.frame(x=runif(4),y=runif(4),z=runif(4))
   X <- ppx(data=df, t="z")
   X

   val <- runif(4)
   E <- lapply(val, function(s) { rpoispp(s) })
   hf <- hyperframe(t=val, e=as.listof(E))
   Z <- ppx(data=hf, domain=c(0,1))
   Z