Class of Point Patterns

Description

A class "ppp" to represent a two-dimensional point pattern. Includes information about the window in which the pattern was observed. Optionally includes marks.

Details

This class represents a two-dimensional point pattern dataset. It specifies

• the locations of the points
• the window in which the pattern was observed
• optionally, a ``mark'' attached to each point (extra information such as a type label).

Warnings

The internal representation of marks is likely to change in the next release of this package.

Author(s)

Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf

See Also

owin, ppp, as.ppp, "[.ppp"

Examples

  library(spatstat)
  x <- runif(100)
  y <- runif(100)
  X <- ppp(x, y, c(0,1),c(0,1))
  plot(X)
  mar <- sample(1:3, 100, replace=T)
  mm <- ppp(x, y, c(0,1), c(0,1), marks=mar)
  plot(mm)
  # points with mark equal to 2
  ss <- mm[ mm$marks == 2 , ]
  plot(ss)
  # left half of pattern 'mm'
  lu <- owin(c(0,0.5),c(0,1))
  mmleft <- mm[ , lu]
  plot(mmleft)
  
  # input data from file
  qq <- scanpp("my.table", unit.square())

  # interactively build a point pattern
  plot(unit.square())
  X <- as.ppp(locator(10), unit.square())
  plot(X)