Class of Point Patterns
"ppp" to represent a two-dimensional point
pattern. Includes information about the window in which the
pattern was observed. Optionally includes marks.
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).
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
marks optional vector of marks
The internal representation of marks is likely to change in the next release of this package.
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)