Aerial view of heather in central Sweden

These data were taken from the website of Peter Diggle. He includes the following description with the data.

Description:

The file "heather" contains a binary representation of the presence/absence (1/0) of heather in a 10metre by 20metre rectangle, digitised to a 256 by 512 array. The file is arranged with 32 entries per line, corresponding to a row-wise scan of the ground-truth 256 by 512 array.

The data were collected in central Sweden by Goran Agren, Toby Fagerstrom and Peter Diggle, in September 1978. Their representation as a 256 by 512 binary array was constructed some years later by Adrian Baddelely.

Usage:

These data are also available in the package spatstat. To reproduce the data as shown in spatstat you can use the following commands in R:

library(ggplot2)
Z <- matrix(scan("heather.txt"),nrow=256,ncol=512,byrow=T)
x <- seq(0,10,length = 256)
y <- seq(0,20,length = 512)
xy <- as.data.frame(expand.grid(x,y))
names(xy) <- c("x","y")
xy$z <- c(Z)
ggplot() + geom_tile(data=xy,aes(-x,y,fill=z)) + coord_fixed()

References:

Diggle, P. J. "Binary mosaics and the spatial pattern of heather." Biometrics (1981): 531-539.