64 Spatial Point Patterns: Methodology and Applications with R
x y id sign
1 0 10 1 1
2 0 0 1 1
3 10 0 1 1
4 2 2 2 -1
5 2 4 2 -1
6 4 4 2 -1
7 4 2 2 -1
The spatstat package also provides its own rudimentary point-and-click interface, clickpoly,
which allows the user to cre ate a window object directly. This was used to crea te the boun dary of
the chorley dataset by tracing a scanned image of a map. See Section 3.9.
Polygon data often contain small geom e trical inconsistencies such as self-inter sections and over-
laps. These inconsistencies must be removed to prevent problems in other spatstat functions.
By default, polygon data will be repaired a utomatically using polygon-clipping code, wh en owin
or as.owin is called. The repair pr ocess may change