the name of the file (a character string) from/to which
data should be read/written.
poly
an object of class "gpc.poly"
Value
read.polyfile returns an object of class "gpc.poly".
write.polyfile does not return anything useful.
Details
The text file representation of a "gpc.poly" object is the
following format:
x1 y1
x2 y2
...
x1 y1
x2 y2
...
For example, a data file for a polygon with 2 contours (a four-sided
object and a triangle) might look like:
2
4
1.0 1.0
1.0 2.0
3.4 3.21
10 11.2
3
21.0 11.2
22.3 99.2
4.5 5.4
The vertices of the polygon can be ordered either clockwise or
counter-clockwise. Right now polygons are not allowed to have holes.