spatstat (version 1.3-2)

ppp.object: 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.

code

ppp

tabular

ll

tab

vector of $x$ coordinates of data points y vector of $y$ coordinates of data points n number of points window window of observation (an object of class owin) marks optional vector of marks

Warnings

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

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).

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))
  X
  plot(X)
  mar <- sample(1:3, 100, replace=TRUE)
  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)